Talk:Köppen climate classification/Archive 3

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Archive 3

Archive 4

Köppen climate classification is obsolete and inaccurate

It would be necessary a paragraph aboout how much useless and unscientific is such classification

eg: it's simply ridiculous that someone could be taken seriously when includes inner Pakistan and even parts of Afghanistan, Tajikistan and Ethiopia in "mediterranean climate" LOL — Preceding unsigned comment added by 78.12.217.244 (talk) 00:46, 21 September 2016 (UTC)

How can anyone could define mediterranean the climate of these cities? Is it a joke?

Tashkent, Uzbekistan (Csa) Dushanbe, Tajikistan (Csa)

Medford, Oregon, United States (Csa)

Sacramento, California, United States (Csa)

Seriously.... the first one have a continental steppic climate, hot and dry summers and extremely cold and dry winters

the other ones have something like oceanic and continental/mild climates.

Not even Los Angeles should be included into Mediterranean climate, it's weather is semi-arid. — Preceding unsigned comment added by 62.10.248.54 (talk) 18:02, 21 September 2016 (UTC)

@62.10.248.54: No matter what objective criteria you use to separate climate, you'll end up with classifications that defy how they're commonly perceived. If you're upset about the Mediterranean climate classification, check out the Trewartha classification system. However, even that one has its flaws: it set out to reduce the area with a Mediterranean climate along the US West coast, but in the process, it nearly eliminated it altogether in California. It also expanded the 'oceanic' zone so much - in an attempt to classify the Pacific Northwest (west of the Cascades) in that zone - that it ended up with the strange result of including parts of Kansas as 'oceanic'.

I'd challenge you to create an climate system with objective boundaries that make everyone happy. Unfortunately, I don't think it's possible. Redtitan (talk) 03:18, 26 September 2016 (UTC)

objective criteria? it's not a matter of objectivity or subjectivity. Koppen classification is obsolete and extremely lacking. The modern climate classifications don't reduce the climate to 2 only parameters like Koppen's one does. The climate is not only the results of the average temperatures and precipitations. — Preceding unsigned comment added by 78.12.218.25 (talk) 13:38, 5 February 2017 (UTC)

Medford. Oregon and Sacramento, California are undeniably Csa. They both have winter rainy seasons and summer dry seasons. Medford is not coastal, and it is at a low altitude, and it is at roughly the same latitude as Detroit, which has a similarly-warm summer. (Detroit is definitely not Mediterranean).

Is the Koeppen classification obsolete? The connection between climate zones and agricultural potential is obvious enough. People in Philadelphia, San Antonio, and Tampa are likely to see their local climates more similar to those of Boston (Dfa), Laredo (BSh), and Miami (Am), respectively. than to the climates of the other three cities within the Cfa classification. Koeppen drew his lines where he did due to ecological realities, and not human perceptions of comfort.

The only way in which the Koeppen classification becomes elite is if some 'new' climate emerges -- perhaps a climate of extreme heat that makes plant growth unlikely irrespective of rainfall. Projections of the future of the Earth suggest that as the sun expands, parts of the Earth (most closely to the equator) will be too hot for warm-blooded animals and perhaps photosynthesis by large vascular plants. Pbrower2a (talk) 07:02, 8 December 2018 (UTC)

This classification is a huge joke, most of Spain is classificated as BSk what is a big mistake when it should be Csa in most of the cases. BSk is only found in Almería, Murcia, Alicante and Ebro valley.

The central Asian locations of Tashkent and Dushanbe have temperatures within the Csa classifications as both have winters at over 0 and plentiful rain along with the hot dry summers. Like it or not, if a winter has a coldest month between 0-18, even if it is much closer to the lower, it is still classed as "mild." — Preceding unsigned comment added by Galen1982 (talk • contribs) 03:43, 1 March 2019 (UTC)

The Koppen system is not obsolete nor inaccurate. Addressing a few concerns on this page: Cfa is too broad. This is a heavily debatable point. However, you have listed exclusively borderline cases. San Antonio is borderline Cfa-Bsk. Philly (and Boston) are both borderline Cfa-Dfa. Tampa is borderline Cfa-Aw. There are many, many examples of Cfa climates that are similar. Austin, Houston, New Orleans, Gulfport, Mobile, Jacksonville, Atlanta, Nashville, Charlotte and Virginia Beach all have mild winters, no dry season, and hot summers. This defines the Cfa climate type.

Csa climates simply mean mild winter, hot, dry summer. They are most often found along the Mediterranean coast (hence the moniker), but can be found in many places on Earth. 0-18 C is very much mild. At 0C, you have no snow. Compare this to the long, cold, snowy winters of zone D, and you will realize that these winters are indeed mild. There may be occasional snowfall, but it does not last for an entire winter. I-82-I (talk) 02:58, 12 May 2020 (UTC)

Class EH

The box at the bottom of the page shows Alpine has 3 classifications "Alpine (ET, EF, EH)". This page and the page it links to does not mention EH. An online search did not show this class either. Can anyone point to a source for this? If not, it should be removed. Hilmar (talk) 13:49, 1 October 2021 (UTC)

@Carders: Hi. I took a closer look at the sources. You are right, the classification scheme in both the Peel et al paper and the Kottek et al paper only has ET and EF. The EH was a made up classification that was due to unsourced edit in which it was added to the box at the bottom of the page. I removed it because there is no such thing as an EH climate. Ssbbplayer (talk) 18:25, 30 October 2021 (UTC)

Brian Head, Utah used as an example

Why is this city listed as an example in the Subarctic or Boreal climates section? To me, it seems to be a poor example since it’s virtually unheard of and has a population of 83. Jamesfett (talk) 10:38, 16 September 2021 (UTC)

 Done I have removed it as it is indeed irrelevant and unheard of. Ssbbplayer (talk) 18:27, 30 October 2021 (UTC)

Possible Double Ups and Other Issues

There are at least five situations which could be said to fit into two classifications. Two of these definitely exist (one which appears two have an obvious answer). The other three are probably theoretical only (one of which appears to have an obvious answer).

A) B or E?

As temperature drops, the threshold for "dry" also drops. E places usually have very low average annual temperatures and at certain levels the dry threshold becomes negative when one does the math. If a place is driest in the summer and has an average below 0°C, it is "moist" at any precipitation level, if the rain or snow is evenly distributed and it is below -7°C it is automatically moist and if the winter is the driest and the average is below -14 it is also automatically moist. However on Climate-data.org I have discovered some very high locations in Bolivia that average below 10°C in every month and are also dry. These places due to their tropical location have low ranges of monthly temperatures so lack the extremely cold months of most E climates, some of them average around 6-7°C but I will use the coldest location in Bolivia recorded on the site as an example. Rio Blanco has an elevation of 4810 m, an average temperature of 2.2 (5.8 in January and -3.0 in June) and just 51 mm of precipitation of which 100% occurs during the summer). We can use these figures to calculate a dry threshold of 324 mm and it only has less than 16% of this figure so it is well and truly desert if a climate can be "B" with all months averaging under 10°C. It seems that such places are typically classified as E regardless of their precipitation.

B) C and D climates with dry months in both summer and winter

When factoring dry seasons for C and D climates, a summer is considered dry if the driest summer month has less than 30 mm and the wettest winter month has at least 3 times the amount of the driest summer month. The winter is dry if the wettest summer month has 10 times that of the driest winter month, regardless of how much the latter month has. This creates the potential for at least one dry month in both summer and winter, which actually exists in some places in Central Asia. The climate data website tends to classify such climates as dry summer, even in the following extreme example. Dehradun is a city in Northern India that is classified on the website as Csa (subtropical dry summer). Here are its rainfall figures, temperatures are not needed for this exercise 63 42 56 16 45 149 545 567 276 96 17 24. The driest summer month is April (16) and the wettest winter month is October (96).So it is correct to say that there is one dry summer month. However the driest month of winter is November (17) and the wettest summer month is August a whopping 567. It is frankly ridiculous to say that overall this place has a dry summer. It is extremely wet from July to September (interestingly the average temperature peaks at May and June). Overall the summer percentage is nearly 84 (1588/1896). It seems to have been classified as Csa on a technicality, the decision to determine a dry summer before a dry winter. Not sure if this is a convention or just used by the website, the Wikipedia article doesn't give examples of this situation. I would think that the best decision here would be to classify the season that is driest overall as the dry season.

C) Af or B?

The theoretical minimum for an Af climate is surprisingly low at 720 mm (60 x 12). In contrast an Am climate has a 1000 mm limit. The example here is theoretical only as I doubt that there are any existing climates with barely 720 mm of rain in a year that are also Af, due to the fact that tropical climates, even without a marked dry season, have uneven seasonal distributions of rain. The Climate Data website gives some Af locations in Brazil with around 1200mm and I doubt any are drier. There is no theoretical maximum precipitation level for a dry climate given that it goes up as the temperature rises. To avoid fence sitting at 60 mm in any month, the fictional example here as 61 mm in every month or 732 mm overall. It has an annual average temperature of 30°C. The rainfall is obviously evenly seasonally distributed, meaning this place needs 740 mm to avoid being dry (30x20+140). I think it would definitely be classed as dry, given that A, C and D climates must be above the dry threshold.

D) Hottest month over 22°C but less than 4 months over 10°C

Again I doubt if this scenario exists. If it did, it would almost certainly contain months below 0°C (or -3°C depending on which one is used). So it would be a D rather than a C. Determining dry seasons isn't the issue here so for argument's sake I will say it has no dry season (Df). The question is, would it be a Dfa because it has a month over 22°C or Dfc due to having insufficient months over 10°C. From what I know of the Mongolian climate, this would appear to be a possible analysis for a given year with an abnormal summer heatwave but probably not a long-term average. Also due to the Mongolian low rainfall, the place would have to avoid being B first.

E) Coldest month under -38°C but 4 or more months over 10°C

The climate over much of Siberia is Dfd, the same as the regular subarctic (Dfc) except with even colder winters including at least one month under -38°C. So what would happen if a place had winters that cold but a slightly longer summer with 4 months over 10°C? Dfb or Dfd? (It is not worth bringing the possibility of a month over 22°C to the discussion here as it would clearly be impossible). This is again more likely to be the analysis for a given year rather than an average figure, in the event of an abnormally warm September. It seems likely that the reason the severe winter was set as low as -38°C was to avoid the possibility of this clash. I live in New Zealand and find anything below zero as severe but even most people living in the US would find a month that averaged -10°C (14°F) as severe.

Other Issues

Dry climates deserve more temperature information. At the moment, depending on what system you use, they are merely classed as hot or cold, depending on if you take an average of above 18°C or all months above 0°C as the cutoff. The latter is particularly problematic, making some "cold" climates having higher averages than some "hot" climates. Dry climates exist with all the temperature classifications of the A, C, D and E categories and this is relevant information that should be incorporated somehow. Pointing out the problem with treating a climate with all months below 0 as "hot" it is true that most such locations would have very hot summers but there are exceptions. According to Climate Data, Oruro in Bolivia (height 3719 m), averages 11.3°C in January, 2.4°C in June, average overall 8°C and 394 mm of rainfall, mostly in summer making it a semi-arid climate. The website uses the under 18 classification, making a BSk, but if you use the alternative definition, which Wikipedia states is currently most fashionable, it is a hot dry (BSh) climate because all months average above zero, when it is clearly not a hot place by any "normal" person's definition). There are also a few dry climates with moderate year round temperatures such as Northern Chile, the coast of Namibia and the high altitude Sana'a in Yemen.

It is theoretically possible to step across the equator from an As (tropical dry "summer") into a BSh climate because you would have a dry "winter" and increase the dry threshold. This points out the limitations of rigidly applying adding 280 for a dry winter, 140 for even distribution and 0 for a dry summer at places that have uniform temperatures. The situation appears unlikely. Savannah climates are rare in the immediate vicinity of the equator which is typically Am or Af, but Climate Data has some South American locations which are as such. They are much too wet to risk being BSh however. A location with an average temperature of 26°C and a dry "summer" needs under 520 mm. When you step across the equator into the dry "winter," this figure increase to 800 mm. The Savannah areas outside of the area very close to the equator seem to exclusively have winter as their dry season.

Finally a "precipitation-heat" index would be a more useful tool for casual data observers than total precipitation. This would be a ratio of total precipitation divided by the dry threshold, possibly multiplied by 100. Climates that were A,C or D would have indexes over 1 (or 100), BS climates would vary from 0.5 to 1 (or 50-100) and BW climates would be under 0.5 (or 50). E climates could have any index. There are points for very cold climates, depending on seasonal distribution, where doing the math would result in negative numbers, these would have to be indicated as index not applicable. The classification system is not imperial unit friendly (not an issue for me as I live in New Zealand). Using rounded figures, to determine dryness for imperial units multiply the annual average Fahrenheit temperature by 0.44 and subtract 14 if more than 70% of the precipitation is in the winter months. For an even distribution, subtract 8.5. For more than in the summer, subtract 3. This will give you the dryness threshold in inches.

Sources: Climate-data.org Galen1982 (talk) 02:58, 1 March 2019 (UTC)

To my comment about potentially crossing the equator from a Bs climate into a semi arid climate I have found on the Climate Data website that this does actually happen in Somalia. This country has only a small portion south of the equator and in this area the wet season is the northern summer. I had only examined South American equatorial regions, not African, I'm pretty sure all of Indonesia is very wet. Anyway it appears that several southern Somalian stations in the Lower Juba state have mean temperatures of around 27°C and annual rainfall of about 550 mm. For a dry "summer" this only just crosses the dry threshold sufficiently to create a dry "summer" savannah (As) climate (540 mm). North of the equator when "winter" is the driest season, the threshold increases to 820, meaning the area is well and truly BKh. Again it reflects the limitations of adding a factor for dry "winter" or "summer" in an area where these terms are virtually meaningless. I suspect I will find a similar situation in some Kenyan stations, though further west in the African equatorial region places tend to be much wetter. The website has literally millions of stations and is clearly automated in terms of computing classifications. Longitude and latitude information are not given for each station so I can't tell straight away for an unfamiliar station in an Equatorial country which side of the equator it is on, but in these instances, having temperature so high and rainfall so low means that it can only avoid being a B climate by having a dry "summer" so it's then a case of looking at the data to determine the drier season. — Preceding unsigned comment added by Galen1982 (talk • contribs) 09:44, 1 March 2019 (UTC)

I think some of these issues are solved by having a fixed order in which a climate is assessed for the various categories. For a theoretical Af/BSh marginal climate, I think you'd first determine whether it was semi-arid and then if not proceed to determine whether if was Af. This avoids the problem of a climate being simultaneously Af and BSh. In practice I doubt there are any marginal climates of this type as climates this warm year round with barely 60 x 12 mm of rainfall tend to be highly seasonal in rainfall; Af climates with consistent monthly rainfall tend to be very wet, with a lot more than 720 mm of rain. One also runs into the problem that for a climate with 60 x 12 mm of rainfall to be BSh it would need to have an average temperature of more than 29C, which is getting towards the hotter limits of climates of this type. Booshank (talk) 19:16, 19 March 2019 (UTC)

On those:

A) The canonical determiner is that a warmest month with an average temperature less than 10C establishes a polar climate. here are hyper-cold deserts such as in the antarctic Dry Valleys which have sub-freezing characteristics of intermittent streams and super-saline lakes. These places are literal snow shadows in which such snow that drifts in literally evaporates. Such places have E climates. The Köppen Climate classification has no distinction for places both arid and polar. A map of Chilean climates shows boundaries in some places between extremely-dry BWk and tundra climates. Since we are not allowed to generate climate classifications for such weird scenarios, we must go with the canon. Almost everywhere else (some parts of Alaska are apparent exceptions), ET typically borders Dfc, Dfd, Dwc, Dwd, or Cfc on its warmer side. In theory a border between ET with Csc, Cwc, Dsc, Dsd is possible -- or for that matter, BSk (some parts of Alaska) or BWk (the cold areas of the Atacama). There is simply no "dry" variant of tundra or ice cap climates (places normally above the clouds?) in the classifcation.

We can be wise and recognize how an extremely cold, hyper-arid place would be.

B) It is conceivable that a place could get the vast majority of its precipitation in the spring and autumn, with very dry months in both the summer and winter. A short, almost Mediterranean-style winter and a short monsoon-like summer would fit this description; maybe April and October are both very dry. In a tropical area this could be Am, recognizing a very short dry season or two. Cm and Dm climates are not defined.

The distinction between Aw and As climates is usually seen as a triviality, especially within a few degrees of the equator. Then again, the rainfall pattern of southern coasts Hawaii is similar to that of the coastal climates of California. Nowhere do low-altitude Mediterranean Csa or Csb climates grade into As. There is no "tropical Mediterranean" climate except apparently in Hawaii on the leeward sides of the islands. Where a Cs/As divide exists is typically at sea or in mountainous areas in tropical areas where altitudes divide A and C climates (usually involving rain shadows in summer but not winter). Toward the equator, lowland Cs climates typically grade into steppe climates as in Morocco and Baja California.

C) If a place lacks the rainfall to establish itself as non-arid, then it is arid, whether it has a marked dry season or not. Places with nearly-even rainfall in the tropics rarely have middling or marginal rainfall on the borderline between arid and non-arid climates. This is more likely in the zones of mesothermal (would be C if adequately moist) or microthermal (would be D if adequately moist), where summer and winter precipitation would be nearly even. The typical gradation into aridity goes through shortening and weakening of moist seasons and intensification of dry seasons. So it is theoretically possible to have a direct transition between Af and BSH climates, but most likely the wet season becomes less wet and the dry season becomes longer and drier.

D) The largest increases and declines in monthly temperature are rarely between the second-warmest or third-warmest and warmest months of a year. Imagine that the May-to-September average temperatures (all Celsius) are 8-17-23-15-9. Such would suggest little persistence of summer heat. Here are the daily means for Detroit, Michigan through the year (January to December). Detroit is inland, and although temperatures rise rapidly in the spring and fall quickly in the autumn the monthly temperatures are stable at the high end and low end.

-3 -2 3 9 16 21 23 22 18 11 5 0

Detroit has a long summer (five months), and the average temperatures are close to each other in December, January, and February, the three coldest months -- and the three hottest months.

There is no summer "spike" in temperature. Detroit is not close enough to any body of water that would mitigate its cold winters and hot summers. (Lake Erie is the wrong direction from Detroit to have that effect, and Lake Huron narrows toward Detroit).

The situation in which a site would have two 'warm' summer months and one 'hot' one like June. July, or August in Detroit is theoretically possible but practically unlikely to the extreme.

E) Dfd, Dwd, and Dsd climates have extreme differences between the hottest and coldest month (at least 48C in range within a year). These places are far from any moderating effect of any ocean (if there were any moderation, then a polar sea would tend to smooth the annual range of temperature into a tundra climate. These places are near the Arctic Circle and the hottest time of the year corresponds with the highest sun and almost a full day of sunshine.Temperatures rise rapidly to this and fall rapidly as well. Not much of the year can be above 10C, so more than three months of temperatures above 10C are highly unlikely. A conflict between Dfb and Dfd as a classification is highly unlikely.

Finally....

F) I find the h/k distinction between "hot arid" and "cold arid" climates confusing. Aridity typically overpowers all other climatic concerns. Unless continually foggy, arid climates have sharper diurnal distinctions in temperature than other climates. If I were to suggest a strict h/k I could think of some criteria other than 0C for the coldest month or 18C as an annual average. For example, San Diego, California at its shoreline is BSk using the 18C average year-round, but even the chilliest month in San Diego is closer to the threshold of 18C for the coldest month (which would be tropical!) than 0C for the coldest month. I would be tempted to use "hk" or "kh" for climates in between the 0C threshold for the coldest month and 18C for the average annual temperature.

Having the initial letter of the thermal regime for a humid climate (BWA or BAW for Timbuktu or Karachi; BWC or BCW for Las Vegas, Lima, or Cairo; BWD or BDW for Turpan or Nukus would dispense with the confusing "h" or "k" without a loss of thermal distinction. For semi-arid locations, BSA or BAS would fit Accra and Maracaibo; BSC or BCS would fit Kalgoorlie and Odessa (Texas) ; BDS or BSD would fit Saskatoon, Odessa (Ukraine), and Ulanbataar. This suggestion would remove much ambiguity. Pbrower2a (talk) 05:07, 20 November 2021 (UTC)

Obsolete distinctions

Here are some letters and parts of combinations that are no longer generally in use,

g signifies a "Gangetic" climate characteristic of much of the Indian subcontinent in which the hottest month occurs before the summer solstice. Temperatures fall from a spring peak (even the Indian tourist council has discouraged people from visiting India in April and May) before the monsoon rains fall and temperatures moderate.

v signifies a Cape Verdean climate in which the warmest month comes after the summer solstice as is so along the California coastline in which the offshore cold current so retards summer warming.

The letters s and w can indicate summer and winter drought, respectively as norms especially in steppe climates, as would fit criteria for humid climates. Thus Mandalay is BShw and Reno is BSks. Nearly-even precipitation or bimodal precipitation (Phoenix) is not noted for arid or semi-arid climates. This is generally deprecated for desert climates.

I have seen these letters attached in old college-level texts for geography and earth sciences. Pbrower2a (talk) 07:25, 20 November 2021 (UTC)

i indicates a climate in which the variation of monthly temperatures is lower than 5°C.Pbrower2a (talk) 15:10, 4 December 2021 (UTC)

Three country examples in each climate section.

I don't understand why G Capo says only three is enough for those cities. In some big countries with a predominant climate zone, it's fine to add more than three country examples. 2607:FEA8:A2A0:1880:5CAC:3B9D:6923:8D98 (talk) 21:11, 14 August 2019 (UTC)

Problem is that people are going to be listing multiple cities, or some irrelevant town of a few people. It's also more fair, by giving preference to big countries with a predominant climate zones, there would be a countless list of cities from USA and China for the Cfa climates as an example, making the article too US-centric or China centric. The page should be a summary, not some sort of a directory. — Preceding unsigned comment added by Ssbbplayer (talk • contribs) 15:07, 13 May 2020 (UTC)

...................

Does anyone have a problem with such cities as London, Paris, Brussels, and Amsterdam being together in a Cfb climate as 'excessive examples'? Cities in the USA, Brazil, Canada, China, India, and Russia are seemingly more scattered as examples of types. If I see New York City and Washington DC having Cfa climates, then Philadelphia and Baltimore are 'listing overload'. If I have Dallas I do not also need Austin or Oklahoma City on the same list. Nobody would confuse the climates of New York City, Cincinnati, Orlando, or Dallas with Atlanta or New Orleans. This said, climatic differences between New York City and Albany; Cincinnati and Cleveland; Orlando and Miami; and Dallas and Lubbock are stark enough.

China, India, and the USA are huge and will have plenty of cities in a few climate zones. One way in which to dodge this is to put 'overflow' into Canada and Mexico for US cities (thus Tijuana instead of San Diego, Ciudad Juarez instead of El Paso, Windsor instead of Detroit. For obvious reasons I can better speak of the United States, which has huge Cfa and Dfa zones that have a big chunk of the world's population in such zones (nearly half of the US population lives in the Cfa zone, which encompasses cities as diverse in climate as New York City (the line between the Cfa and Dfa zone passed through it during the twentieth century), three large cities in Florida now close to the Cfa-Aw line (St. Petersburg, Tampa, and Orlando, which will probably be in the Aw zone should most projections of global warming be true), , Dallas (which can feel much like a hot-desert BWh location), or more "classic" locations such as Atlanta and New Orleans. The United States has many people living in cities in the Dfa zone, and having Omaha, Chicago, and Boston as examples of Dfa climate (Windsor is one way of recognizing Detroit) illustrates that the Dfa zone is common in America if limited in range elsewhere. The Csb zone is in a narrow band in the USA, but it does extend from Seattle to Santa Barbara.

The Csa climate appears not far inland from the Pacific coast in Sacramento, but there are few giant cities in America with such a climate. Roseburg, Oregon can illustrate this.

I'm not going to complain if one lists national capitals. Remember, though: American states can be huge and can have great regional divides in climate. Small towns can be mentioned if they are illustrative, and they are particularly strong if resorts -- especially ski resorts. Those are likely to be well known worldwide. This said, if you have Prague you don't need Brno, and if you have Warsaw you do not need Lodz.Pbrower2a (talk) 15:10, 19 November 2021 (UTC) modifications Pbrower2a (talk) 15:16, 4 December 2021 (UTC)

Annual Rainfall

Why are the no annual rainfall graphs?? 41.116.21.27 (talk) 18:24, 17 February 2022 (UTC)

Koppen Climate Classification For the US state of Maryland Has to Go

The Koppen Climate rating for Maryland is completely inaccurate (for "Winter climate"). Except for Western Maryland (the only part that is accurate).

The Koppen Climate survey claims that Maryland winters are "mild to cool". False. A large percentage of winter days in Maryland are quite cold. A large percentage are also "cool". Only a small percentage are "mild".

It is inaccurate for most of the state, including the following regions: Central Maryland, Southern Maryland, and the Eastern Shore of Maryland (most of the state). This Koppen-misinformation is posted on (maybe) over a hundred Maryland-related Wikipedia articles.

A superior substitute for the incorrect Koppen Climate classification for Maryland must be found. The KCC should be removed from every single Maryland-related Wikipedia article.

Chesapeake77 (talk) 00:17, 3 March 2022 (UTC)

The definition of climate type D

The average temperature of the coldest month in climate type D should be at or below 0° or -3°, not just below. Right now the definition would mean a climate type with the average coldest month of 0° or -3° wouldn’t fit into climate type C or climate type D. It’s a small nitpick but it bugs me. IdK6 (talk) 23:06, 4 March 2022 (UTC)

About the ice cap climate

The Ushakov Island, located in the far north of Russia, is an area of the northern hemisphere that has an ice cap climate except for Greenland and some other alpine regions. Seele2021 (talk) 04:32, 16 March 2022 (UTC)

New York City in the Cfa section example

If 3 US cities are in the Cfa section example, New York City should be in there rather than Washington DC, because New York City is one of the largest cities in the world with the Cfa or Humid subtropical climate zone. --TVTU Editor (talk) 02:19, 14 September 2021 (UTC)

The problem is that New York City is near a borderline between Cfa and Dfa climates. Washington DC isn't. The Cfa/Dfa line was probably just south of Coney Island in 1900 and passed through midtown Manhattan around 1940, and through the Bronx around 1970. Global warming (and the heat-island effect) are real.I would guess that some outlying suburbs to the west and north are still Dfa.

I prefer that cities not clearly in one zone not be listed here should there be multiple zones in an area. Greater Denver has places with Dfb, Dfa, and BSk climates. San Diego, depending on location, can be BSh or BSk (a matter of choosing the threshold of temperature), Csa, or Csb...

It could strictly be a matter of taste. Washington, DC is farther away from places with Dfa climates than is Philadelphia or New York City, some of whose suburbs are Dfa. Pbrower2a (talk) 15:26, 19 November 2021 (UTC); Modifications Pbrower2a (talk) 15:16, 4 December 2021 (UTC)

The KCC classification of Washington D.C. winters is completely innacurate. It says that winters there are "mild to cool". Not true, a large percentage of winter days in the Washington Metro area are quite cold and a large percentage are cool. Only a small percentage are mild.

See also the section on this Talk Page about KCC innacuracies in Maryland, which borders Washington D.C.

Chesapeake77 (talk) 11:54, 12 May 2022 (UTC)

Deprecation / Adding Koppen Climate Classification to Wikipedias list of unreliable sources

I suggest that this be done. An in-depth read of this Talk Page will tell you why.

For the state of Maryland the KCC (and it's innacurate description of winters in much of the state) is unnaceptable. This misinformation is on nearly a hundred articles for the state.

The KCC is outdated and innacurate for many parts of the world. A superior replacement should be found.

And it should be added to one of Wikipedias lists of unreliable sources, or otherwise deprecated.

Chesapeake77 (talk) 12:01, 12 May 2022 (UTC)

The Koppen system is still the most widely used classification system in the world. Also "cold" is subjective...you believe that Maryland winters are cold, however someone in Canada or in the midwestern and/or northeastern portions of the US may view Maryland's winters as mild to cool. By American standards, Maryland winters are generally mild to cool. G. Capo (talk) 14:49, 24 May 2022 (UTC)

Recent sockpuppet edits

Recently this article has been edited extensively over several months by User:Paulistafan, who has been blocked as a sockpuppet account of Honduras200010. The edits of that account's many sockpuppets have focused primarily on climate, and many of their edits have been reverted on substantive grounds even before any notice had been given to the fact that they were accounts of a blocked user. Since there have been many intervening edits by other users, it isn't possible simply to roll back to the state before the user's first edit. Please review this account's (and, for that matter, any other of the sockpuppets') edits for reliability and fix as appropriate.

Gwiztiktok is in all likelihood the latest incarnation (and I've submitted that account for investigation). I've undone that user's changes. Please be on the lookout. Largoplazo (talk) 04:02, 2 November 2022 (UTC)

Baja California Sur is shown as an independent state.

For whatever reason, the state border between Baja California and Baja California Sur is shown as an international border. Baja California Sur is not an independent state. Erbeilas (talk) 23:46, 30 December 2022 (UTC)

I dont know what to do about this.

I can only only thank the creators of the map for classifying the climate types of the Caspian sea! PAper GOL (talk) 14:53, 12 July 2023 (UTC)

Discrepancy Map/Examples

According to the map, Berlin is in Dfb, but is listed as an example of Cfb in the article. There are possibly other such discrepancies. Vilem Liepelt (talk) 11:45, 5 July 2022 (UTC)

Well, The map is based on (1980-2016) averages and Berlin's Coldest month avg in that period appeared to be below 0C. This map uses 0C isotherm for C/D borderline if you see the 26th reference(Nature study). Same can be said for Budapest,Bratislava etc.

Berlin's coldest month avg in 1991-2020 normals is above 0C. Therefore it is Cfb and not Dfb. PAper GOL (talk) 15:37, 12 July 2023 (UTC)

Kabul

This city is both Dsa and BSk somehow. There has not been any action for this so far. PAper GOL (talk) 14:56, 12 July 2023 (UTC)

I did the calculation myself. Its Semi-arid. it receives a liitle above 30% of its precip from Apr to Sep.PAper GOL (talk) 06:15, 25 July 2023 (UTC)

Lack of sourcing

Just one location among the lists of examples in this article is sourced. A comment in the #Kabul section immediately above this reads "I did the calculation myself" and I'm starting to wonder if many of the examples were placed here by editors doing the calculations themselves. If so, that's original research. In case anyone's going to argue that this is a matter of routine calculation, which might be a reasonable justification, I'll point out that, in that case, the factors that go into the calculation need to be sourced. It's OK to take 2 and 2 and sum them to 4 without a source for the 4, but then you still need a source for the 2 and the 2.

Ironically, there's an editor who repeatedly introduces material here and in other climate articles and climate sections who does provide soruces (in the edit summaries), and that editor's contributions are routinely reverted. Sometimes grounds for the reversions are stated in terms of the sources not being reliable (I revert them because the editor is a sockpuppet of a blocked account), but, then, how are examples with no sources at all any better than those?

I've just tagged the article accordingly. Largoplazo (talk) 10:03, 25 July 2023 (UTC)

Hi,@Largoplazo

Looks like you are talking about me. Can you summerize the problem?

I hadn't received any answer after 13 days about the Kabul problem.(my bad,maybe should have waited more?) I dont know if there is way to cite sources directly in edit summeries.Most of my additions are based on data from NOAA other official agencies. The calculations I used are mentioned in semi-arid cliamate and desert climate.

Besides, A (more citations needed) template is NOT a minor edit, is it?PAper GOL (talk) 10:33, 25 July 2023 (UTC)

Hi, PAper GOL, and welcome to Wikipedia (I see you just started editing this month). Yes, your remark is the one that led to my review of the article and my observation about the lack of sourcing. But I'm not singling you out, my observation is about the overall state of the article, which wouldn't have left you to understand that you should proceed any differently from all the other contributors. I summarized the problem already in my first paragraph—if something wasn't clear, can you tell me what it is? The key to it is the article I linked to, WP:No original research.

If your additions are from NOAA, then you should cite the NOAA sources you're getting them from. See Help:Referencing for beginners.

About the "minor" edit: I, like many users, use various tools that are available on Wikipedia to automate tasks such as tagging pages, nominating them for deletion or raising them for discussion, leaving warnings for users, etc. I use Twinkle for a number of these tasks, including tagging articles. Twinkle apparently marks these edits as "minor". And it shouldn't, going by Help:Minor edits, which lists among reasons not to mark an edit as "minor", "Adding or removing visible tags or other templates in an article". Oh, but wait: In the Exceptions section at the end it says "Additionally, bot accounts usually mark their edits as minor in addition to the 'bot' flag". But Twinkle isn't a bot, and it doesn't mark the edit as a bot-created one. This is a matter to raise at Wikipedia talk:Twinkle. Largoplazo (talk) 10:58, 25 July 2023 (UTC)

Now I see what you mean. Well, the way I calculated the data for Kabul is shown below:

The threshold in millimeters is determined by multiplying the average annual temperature in Celsius by 20, then adding:

(a) 280 if 70% or more of the total precipitation is in the spring and summer months (April–September in the Northern Hemisphere, or October–March in the Southern), or

(b) 140 if 30%–70% of the total precipitation is received during the spring and summer, or

(c) 0 if less than 30% of the total precipitation is received during the spring and summer.

I used the year daily mean figure stated in Kabul's weather box.

(the source for daily mean and monthly precip)

20x 12.1 = 242

the total precipitation is in the spring and summer months (April–September in the Northern Hemisphere, is 105.8 when summed.(with calculator)

Total annual precip is 312.

105.8÷312=0.339(~34% done by calculator)

so I had to add 140 to 242. The result would be 382.

If the annual precipitation is less than 50% of this threshold, the classification is BW (arid: desert climate); if it is in the range of 50%–100% of the threshold, the classification is BS (semi-arid: steppe climate).

312 is in 50%-100% of the threshold(382). That is how I reached the BS.

The calculations are a bit too much for Classifying the type. There is high chance of making a mistake. But its the best the way for me to verify.

Maybe I should write my next summaries in the talk page.

I dont know if that is routine Calc or its WP:OR. PAper GOL (talk) 12:57, 25 July 2023 (UTC)

I assume what you are saying is (The data we use to classify the climate type should be referenced). The sources I used are already referenced to a reliable source in their own article and I just need to re-cite them in this article. See this Kabul reference which I copy-pasted from Kabul article's weather box.PAper GOL (talk) 19:41, 25 July 2023 (UTC)

References

Letter H

Some E group examples have ETH and EFH climates. It seems that the H letter is for highland locations but no explanation is provided for it. Are there any reliable sources for these classes?PAper GOL (talk) 03:45, 9 August 2023 (UTC)

I found no sources that would use ETH/EFH. Those used for creating maps dont use them either. They were removed. PAper GOL (talk) 13:09, 14 August 2023 (UTC)

I also got problem with locations that can be Df or Ds. One example is Urmia that is classified Dfa but has 3 or 4 dry summer months that make it viable for Dsa. It receives 39% of its precipitation in the high-sun half. Mostly in spring — Preceding unsigned comment added by PAper GOL (talk • contribs) 13:36, 11 August 2023 (UTC)

Math parse error

In the Overview section, there is a math parse error. It reads "Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "http://localhost:6011/en.wikipedia.org/v1/":): {\textstyle 100-\left ( \frac{\mathrm{Total\,Annual\,Precipitation\,(mm)}}{25} \right )}". I don't know how to fix it. Can someone help? TypoEater (talk) 17:42, 27 September 2023 (UTC)

The hot/cold arid situation

I have brought it up before, and I'm bringing it up again; is there anyone with sources on this? I have only seen a 0C isotherm be used for cold/hot deserts once, and only for California. I'm not sure why these are consistently being added. Uness232 (talk) 23:22, 13 August 2023 (UTC)

There are some sources in overview section where you forgot to edit. Maybe they help you. If they didn't you can remove.PAper GOL (talk) 12:13, 14 August 2023 (UTC)

I have another problem regarding Cw/Dw climates' ALTERNATIVE defintion (at least 70% of annual precip falling in high-sun half). This one is also totally unsourced. Then we have this EFH thing used in this article without mentioning what H actually means.PAper GOL (talk) 12:22, 14 August 2023 (UTC)

The sources there are for BWn, not for h/k. If you can not find a source for Cw/Dw, delete it too. Uness232 (talk) 12:24, 14 August 2023 (UTC)

See Talk:Semi-arid climate for previous discussions.PAper GOL (talk) 04:57, 11 October 2023 (UTC)

Relevance of including German words for the different climates?

The Köppen-Geiger classification was initially created in part by a Russian-German person, and without knowing the German terms for the various climates, the letters (especially for the B subtypes) seem nonsensical. Would it be well advised of me to add these in an etymological section, or would that be original research (of which I have been tried and convicted many times)? Ellenor2000 (talk) 07:01, 2 January 2024 (UTC)

If you cite a reliable source, then it isn't original research. Surely you've been told that before, no? In this case you can go right to the Urquelle: [1], p. C14. And it's certainly relevant. Largoplazo (talk) 10:46, 2 January 2024 (UTC)

Dispute over at Talk:Budapest

Regarding its climate classification per Köppen. I call interested editors to chime in. Uness232 (talk) 16:54, 9 January 2024 (UTC)

I reiterate this request; there needs to be more of a discussion and a consensus on this, as it in fact touches on much more general concerns. Uness232 (talk) 16:38, 11 January 2024 (UTC)

RfC: Generalizing climate type descriptions when classification systems conflict

Are more general descriptions of climates acceptable on city/region climate sections if climate classification systems conflict?

Three options come to mind here:

• Option 1: Climate descriptions should not be generalized, even when classifications conflict. This leads to the structure given below being the only acceptable description:

Budapest has a humid subtropical (Köppen: Cfa) or oceanic (Trewartha: Doa) climate.

• Option 2a: Climate descriptions could be generalized, but this should be kept to cases where intractable disputes form due to wording and/or climate type (see Talk:Budapest#Climate for example); therefore the structure given below would also be acceptable in certain circumstances:

Budapest has a humid temperate climate (Köppen: Cfa, Trewartha: Doa).¹

• Option 2b: Much like 2a, but without the dispute requirement. Climate types could be generalized at will as long as climate classifications conflict.

¹ Keep in mind that both Köppen and Trewartha place Budapest into a climate class within the scope of a humid temperate climate (humid subtropical and oceanic respectively). For some cities, the category might need to be broader; Portland, Oregon would simply have a temperate climate under this scheme, as that is the first level of intersection between Mediterranean and oceanic climates. Despite this, within the rules of Köppen and Trewartha, a point of no overlap is mathematically impossible; and it is vanishingly rare to see another classification besides these two on a city page.

Uness232 (talk) 00:27, 21 January 2024 (UTC)

Comments

• Comment/Neutral: I am staying neutral on this; but some context may be necessary as this is a rather exceptional RfC. These are three plausible positions that have been extracted out of Talk: Budapest#Climate, they are no means all of the positions on that page. They are simply what seem to be the most pragmatic and/or least radical ones (i.e. ones that do not require the entire classification conventions to be changed). The point of this RfC, then, is to set precedent and convention, as compromises like these seem to be able to calm people down about the controversial applicability of the word 'humid subtropical' to Cfa-class climates, the difference between local and global climate classifications, or climate class disputes that result from mapping, station or climate normal differences. So the question is, are these compromises compliant with Wikipedia policies and/or guidelines? (One more thing; the reason this RfC is here and not in climate classification is due to the much higher visibility of this page. A consensus obtained here will undoubtedly be more general.) Uness232 (talk) 00:43, 21 January 2024 (UTC)
• Option 1 and it's not even really a choice but the only correct result in my mind - I think it's pretty obvious that in the event that a place is on the edge of two or more Köppen classifications, all of them will be mentioned in RS. Options 2 and 3 are clearly WP:SYNTH. SportingFlyer T·C 01:29, 21 January 2024 (UTC)

  The issue is not that however. This specifically has to do with what we can do when two climate classifications, virtually always Köppen and Trewartha, put a climate in two different zones and (usually) a dispute breaks out with an infinitely cycling argument on pedantic issues of climate naming and such. Again, see Talk: Budapest#Climate, valuable time gets wasted to a deeply frustrating argument mostly on what to name the Cfa climate. (later note: What I meant by this was not that the disputes always start with the distinctions between Köppen and Trewartha. Sometimes other reasons are also involved like naming standards, as PAper Gol pointed out. This is simply a proposed solution to some of these disputes where policy-related reasons are put forward to deem a certain wording problematic, and we can generalize the climate type due to differences between classifications.) 2a and 2b are proposing to use a more general category that includes both of the climate subtypes being talked about to alleviate this problem. For example, both Mediterranean and oceanic climates are temperate climates by definition, so one could argue that no new information is being ‘synthesized’, so to speak. Uness232 (talk) 01:48, 21 January 2024 (UTC)

  Then just say city X is in Köppen classification Y and Trewartha classification Z. Anything else is synth. It's really not hard at all. The Cfa climate also has multiple titles but also has a clear title on what to call it - humid subtropical. SportingFlyer T·C 11:34, 21 January 2024 (UTC)

  This clear title is the main reason there was a long dispute in Budapest talk and ended to this RfC. It wasn’t used by Köppen. Some sources use it and some don’t, if some don’t agree with the naming( like the Hungarian meteo service), then how is it a clear title?PAper GOL (talk) 11:46, 21 January 2024 (UTC)

  You also simply assert WP:SYNTH without any argumentation whatsoever. Let's look at Portland again for example: Köppen labels it Csb, and Trewartha labels it Do. However, Köppen's C class is explicitly named "temperate", and Trewartha's D class is explicitly named "temperate". Therefore both climate classifications explicitly call the city temperate; that is not a synthesis of information "not stated by either source", as both the sources explicitly call the city temperate. WP:NOTJUSTANYSYNTH. Uness232 (talk) 11:57, 21 January 2024 (UTC)

  You both are far too deep into the weeds here on this discussion. Be specific. I don't think there's anything wrong with a sentence like "Portland, Oregon is classified as temperate by both the Köppen and Trewartha climate classification systems" as long as the specific classification is also mentioned, which makes it somewhat redundant. Also, humid subtropical is clearly used on Wikipedia while humid temperate clearly states that it is not part of the Köppen classification on its Wikipedia page, and consistency is important. SportingFlyer T·C 12:08, 21 January 2024 (UTC)

  Well that's almost exactly the wording I propose in 2a and 2b that could (not should, necessarily) be used if there's an intractable dispute, only putting the classifications in parentheses, as is usually done: "Portland, Oregon has a temperate climate (Köppen: Csb, Trewartha: Do)." Csb and Do can be linked, if it would help consistency and/or clarity.

  You seem to claim that this dispute could have been easily resolved by convincing people of humid subtropical; and yes, I thought so too, before there were 110 comments on the section, mostly arguing against the use of humid subtropical (using arguments based on policy oftentimes). This lasted for multiple weeks. The lack of consensus achieved there shows that there are simply too many ambiguities that surface when local and global classifications disagree so sharply that global WP:RS deeply conflicts with local WP:RS, when maps show inconsistencies, or when a climate class has a less-than agreed upon name. In that sense, this is a practical solution; a band-aid, so to speak, to still keep the systematized nature of climate classification on Wikipedia (so still generally discouraging unsystematic descriptive sources and encouraging systematized climate classification sources), while largely resolving other issues that people fall into long, useless discussions on. It is the final compromise reached over there, and I'm asking whether it is one acceptable solution (of many) in future cases.

  A simple assertion calling it WP:SYNTH when it is not at all that clear cut is not productive, either. Uness232 (talk) 12:37, 21 January 2024 (UTC)

  I still think it is very clear cut - very easy to use global sources as everyone else does - and with that I bid you good day. SportingFlyer T·C 12:49, 21 January 2024 (UTC)

  If it was indeed so easy, why was there a weeks long argument over at Budapest? And why did users experienced in climate classification not simply force a consensus on the "clear cut" issue, despite my publicizing of the dispute here, on the Weather WikiProject and other places? Maybe there exists a Wikipedia in your head in which everyone agrees on how to interpret WP:RS, how to think about consensus, what sources to prioritize, etc; but that is not at all the Wikipedia we have. Where, in WP:RS, for example, does it say that global climate classifications are better sources than local ones? You seem to imply that something along those lines is the case here, but I do not see that anywhere. So, many people use local WP:RS to challenge naming/classification, and some even propose much more radically altering the way classification works on Wikipedia, prioritizing local WP:RS (this latter one is not plausible in my personal opinion, but it was an argument that came up on Talk: Budapest). Are you willing to simply say that they are acting "against policy/guidelines"?

  If we are discussing the supposed ease of using 'global sources' and non-universal naming schemes on city pages despite what seems to be very clear evidence of the contrary on that talk page; I would sincerely invite you to take a look at the dispute and tell me with what argument would I have been able to "easily" solve the issue in favor of using humid subtropical. I tell you that the status quo was virtually impossible to enforce on Budapest due to these ambiguities, but you do not even seem take into account my argumentation on why it has been difficult, why it is not clear cut, and simply contradict (see the pyramid at WP:TALKNO) what I say with very little supporting argument. If that is all of what you are planning to do, I bid you good day as well. Uness232 (talk) 13:42, 21 January 2024 (UTC)

• Option 2a, there is not actually synth problem here.

In the Budapest example we can call it simply temperate as Group C of Köppen is accepted to be temperate. Cfa is mostly considered humid subtropical but not all sources agree on that, but they all agree that Cfa is a temperate climate subtype. It is just a matter of proper wording and writing if the statement is likely to be WP:SYNTH.PAper GOL (talk) 09:07, 21 January 2024 (UTC)

Though synth problem might occur when two or more classifications are used, in which option 1 would be better but still we can use a broader term for subtypes as in option 2a. example:

In Köppen climate classification, Portland(Oregon) has a temperate climate classified as Csb, while under Trewartha classification Portland’s climate is classified as Do.PAper GOL (talk) 09:27, 21 January 2024 (UTC)

"Though synth problem might occur when two or more classifications are used," Well this is specifically for instances where two (there's very rarely any more than two) classifications are used. Are you saying that WP:SYNTH problems would arise then? If so would that not invalidate your argument for the usage of 2a?

A lot more simply, your argument looks like it contradicts itself here; could you explain what you mean? Uness232 (talk) 10:50, 21 January 2024 (UTC)

I’m slightly towards 2a, because for locations and regions which borderline classifications cause confusion or dispute, it’s better to use more general terms

There won’t be synth problems (it might occur but only if the text is written in bad manner). .PAper GOL (talk) 11:15, 21 January 2024 (UTC)

I see what you mean. So you only think that it would only be WP:SYNTH if the proper general name is not used (i.e. if a Csb/Do climate is labeled as oceanic). That makes sense, thank you for the explanation. Uness232 (talk) 11:39, 21 January 2024 (UTC)

• Option 1 - anything else falls too close to WP:SYNTH or potentially even cherry picking. If there's ambiguity, we should report the ambiguity, rather than pick whichever we like more, even when it comes to something as mundane as the weather..

DarmaniLink (talk) 08:36, 19 February 2024 (UTC)

@DarmaniLink I understand that you think it is WP:SYNTH, but I think you misunderstand what this is about. Perhaps this is just the complexity of the issue, but no option would involve picking "what we like more". As I've told someone else in a previous comment:

Let's look at Portland again for example: Köppen labels it Csb, and Trewartha labels it Do. However, Köppen's C class is explicitly named "temperate", and Trewartha's D class is explicitly named "temperate". Therefore both climate classifications explicitly call the city temperate; [calling the city temperate] is [therefore] not a synthesis of information "not stated by either source", as both the sources explicitly call the city temperate.

Again, this might not change your opinion that it is WP:SYNTH as you might think that for another reason; but I did want to offer this as a clarification on this admittedly complicated issue. Uness232 (talk) 13:53, 19 February 2024 (UTC)

admittedly, i should have worded that better but, in cases where the two are different, picking one or the other would be a matter of preference, right? Not every single instance, i'd imagine, as as clearcut as those two. Of course I'm no expert either, and im willing to learn DarmaniLink (talk) 14:16, 19 February 2024 (UTC)

@DarmaniLink It is important to note here that there are only two systematic climate classifications used on Wikipedia, Köppen and Trewartha. This is because other climate classifications do not have sufficient sourcing, or are genetic (boiling down to climatologist opinion, and therefore always mentioned separately). Based on the rules of Köppen and Trewartha, a zone of no overlap is vanishingly rare. Because of the similarity of the two classification's rules, even differences in classification are only possible in a limited amount of circumstances, and all of these (except one rare case that I have realized recently, but would not be a problem) have points of overlap:

• Trewartha allows for tropical climates to be qualified 'rainforest' if they have 1 or 2 months with less than 60mm of precipitation, while Köppen does not. If this happens, the climate can simply be called 'tropical', as both main classes are called 'tropical'.
• A climate with winter temperatures over 0C, summer temperatures over 22C, and less than 8 months over 10C, can be qualified as one of the subtropical subtypes of Köppen, while Trewartha would classify that climate as oceanic. This is by far the most common and most disputed climate zone, causing disputes on the New York City, Budapest (also see Talk:Budapest#Climate)), Milan pages, and many others. The solution here would be to classify the climate as 'temperate', as both classes 'C' in Köppen and 'D' in Trewartha are called temperate.
• Csb types are an exception in Köppen; they are still called Mediterranean, despite being in the cool-summer zone. Many of these climates (like Portland, Oregon, Seattle and others) have less than 8 months of temperatures over 10C, which means that Trewartha would put them in the oceanic zone. The solution here is the same as the previous one, call it temperate, as both classes 'C' in Köppen and 'D' in Trewartha are called temperate.
• Dry-summer or dry-winter continental climates of Köppen are subsumed into the humid category in Trewartha. The solution here is to call the climate simply continental.
• In terms of boreal/subpolar climates, the difference between subpolar oceanic and subpolar continental climates are 0C in Köppen and -10C in Trewartha, the solution here would be to simply call the climate boreal/subpolar.

And finally, the issue that could arise (but is unlikely to for numerous reasons):

• I've recently remembered that the semi-arid climate thresholds are ever-so-slightly different. This could cause a point of no overlap in a very small amount of places, and the solution there is simple, to not simplify, and talk about the two classifications seperately. Either way, this is unlikely to cause problems, as the climates that lead to arguments for simplification are almost always in point 2 and 3.

Uness232 (talk) 16:08, 19 February 2024 (UTC)

Wouldn't this still just cause the same problems as before though, possibly, of people arguing whether or not a definition applies or if you can reasonably believe that the intersection in some cases can be described as such?

It seems like you would need to put a source on "temperate" for example.

Would it be feasible to make a template to algorithmically generate the intersection, along with a source for that intersection, that can be decided on prior? DarmaniLink (talk) 13:52, 20 February 2024 (UTC)

@DarmaniLink Sorry for the late reply. Theoretically this could happen, but in practice this is basically impossible. This is a little tougher to explain, but main types in Köppen or Trewartha are generally not cited for naming (tropical climate, temperate climate, continental climate and subpolar climate are the ones that would be destinations for "generalization"), because they have uncontroversial WP:COMMONNAMEs. Even subtypes can go uncited sometimes due to uncontroversial naming; see Beijing, Paris, Barcelona as examples. Except for a few subtypes (principally Cfa, which is quite controversially called humid subtropical), the most common names of these climate types in these classifications are very rarely disputed due to usages dating back to the original papers. All of the solutions that could be applied here are therefore widely agreed upon.

Furthermore, this solution was not meant to be an idealistic one but a band-aid of sorts; the problems I've encountered while arguing about these things being twofold:

1) Sometimes local WP:RS contradicts global climate classification so much that it gets used to paint the global climate classification for that location as an uncommon viewpoint or even WP:FRINGE. For example, showing many local sources, editors have argued for the removal of "humid subtropical" from Budapest, because sources calling it continental based on some local classification far outnumbered those using Köppen. However, using local classifications on Wikipedia is also untenable, as long as all the pages for climate types are based on Köppen (I have attempted to change the status quo on this, to no avail). As I've said before:

What will we do when Portland, Oregon has an oceanic climate according to local literature, but the climate page says that oceanic climates need to not have dry summers?

Therefore, the solution currently reached at Budapest#Climate has been the only one that ended up being stable.

2) The few subtypes that can have name disputes (humid subtropical for Cfa, Mediterranean for Csb) almost always have their disputes brought up in transitional locations (due to the lack of zone fluidity in climate classification). Therefore, generalizing climate type (as long as we have another systematic classification to back the generalization) can solve those problems as well, as there are no disputes on main types.

As for the template idea, I am unfortunately not experienced enough in the creation of templates to know whether that would be feasible, but it would be great; not just for calming discussions, but for standardizing and beautifying format. Uness232 (talk) 00:00, 23 February 2024 (UTC)

Semi-protected edit request on 13 March 2024

• Cartago, Costa Rica (Cwb) RomuloVG (talk) 02:16, 13 March 2024 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Shadow311 (talk) 16:13, 13 March 2024 (UTC)

Köppen-Geiger Map 1991-2020 now available in Commons

1991-2020 is the official current base periode (WMO), so I suggest we should switch to the updated map now in Commons for this article. And there are some real differences in climate zones compared to the current map, which is not updated any longer. Orcaborealis (talk) 19:20, 19 April 2024 (UTC)

@Orcaborealis I agree. The 1981-2016 maps are also used in many country maps and those should also be changed to newer versions, which would require a concerted effort. I would suggest alerting some WikiProjects.

As a further note, there are also the predicted climate maps, which are problematic in their own right as they assume the rather extreme RCP8.5, and can now be replaced with more likely scenarios (according to papers cited in the RCP article, RCP3.4 is the most likely) as we now future maps for a wide variety of RCP scenarios. Uness232 (talk) 03:38, 20 April 2024 (UTC)

Color for Csa is impossible to see in illustrations

When looking at Csa in the diagrams (maps) the Csa color is nearly impossible to distinguish from the background grey color. For examples:

• Köppen_climate_classification#/media/File:Koppen-Geiger_Map_C_present.svg
• Mediterranean_climate#/media/File:Cs_climate.png
• Mediterranean_climate#/media/File:Koppen-Geiger_Map_Csa_present.svg

I understand that the colors of the various climates are based on the official Kopeen color conventions, but I'm wondering if there is some way to improve the contrast of Csa color somehow.

Or, if that is not possible, changing the background color (of the "no climate zone" map regions) from light grey to some other color ... at least in the few maps that focus on Csa/Csb climates.

Noleander (talk) 04:10, 18 May 2024 (UTC)