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(Note: I am no climatologist or anything, I just did this for fun! Feel free to give feedback or criticize as necessary.)
I created this system over the weekend, and I took a bit of inspiration from the Koppen system, the system on the BONAP website, Holdridge Life Zones, and the Worldwide Bioclimatic Classification System.
Things you may need to calculate in order to find climate:
Yearly Average Biotemperature With No Maximum Limit: Find the sum of the mean temperatures of all months, but round any temperatures below 0°C to 0°C. Divide it by 12.
Yearly Wetness Index: Multiply the yearly biotemperature by 58.93 to estimate potential evapotranspiration (this actually works pretty well, and is much easier to calculate than the more complicated equations). Divide annual average precipitation by this value to get the aridity index.
Summer Wetness Index: Find the biotemperature of the hottest 3 months, multiply it by 58.93. Add the average precipitations of these months (in mm) and multiply by 4 to estimate a whole year of this level of precipitation. Divide the precipitation value you found by the potential evapotranspiration value.
Winter Wetness Index: Do the same thing as above, except for the coldest 3 months.
Temperature Continentality: Find the standard deviation of all average monthly temperatures and multiply by 100.
Precipitation Seasonality (Tropical Climates Only): In tropical climates, where there is no real hottest months, we find precipitation seasonality instead. Find the standard deviation of the average precipitation amounts in each month. Divide the yearly precipitation by 12 (mean monthly precip.) , and divide the standard deviation by the mean.
There are 7 temperature zones:
Zone 1 (tropical): Yearly biotemperature above 24°C
Zone 2 (subtropical): Yearly biotemperature 18-24°C
Zone 3 (warm temperate): Yearly biotemperature 12-18°C
Zone 4 (cool temperate): Yearly biotemperature 6-12°C
Zone 5 (boreal): Yearly biotemperature 3-6°C
Zone 6 (subpolar/subalpine): Yearly biotemperature 1.5-3°C
Zone 7 (icecap): Yearly biotemperature 0-1.5°C
Climate Types:
Zone 1 (tropical): Yearly biotemperature above 24°C
1w (Tropical wet and dry): Yearly wetness index above 0.7, precip. seasonality above 50
1s (Tropical semiarid): Yearly wetness index between 0.25 and 0.7
1d (Tropical desert): Yearly wetness index less than 0.25
Zone 2 (subtropical): Yearly biotemperature 18-24°C
2f (humid subtropical): Summer, winter, and yearly wetness index all fall above 0.7
2m (subtropical dry summer): Summer wetness index is below 0.7, winter wetness index is above 1.
2w (subtropical monsoonal): Summer wetness index is above 1, winter wetness index is below 0.7
2s (subtropical semiarid): Yearly wetness index is between 0.25 and 0.7 and neither summer or winter have wetness index above 1
2d (subtropical desert): Yearly wetness index less than 0.25
Zone 3 (warm temperate): Yearly biotemperature 12-18°C
For this classification system, I use "continental" to refer to a large temperature range. It doesn't necessarily mean that winters get snow. While hypermild climates were originally created to distinguish subtropical highland climates from oceanic ones, some temperate coastal locations do have this climate.
3fh (warm temperate humid hypermild): Yearly temperature continentality is below 300. Summer, winter, and yearly wetness index all fall above 0.7.
3fo (warm temperate humid mild): Yearly temperature continentality between 300 and 650. Summer, winter, and yearly wetness index all fall above 0.7.
3fc (warm temperate humid continental): Yearly temperature continentality above 650. Summer, winter, and yearly wetness index all fall above 0.7.
3mh (warm temperate dry summer hypermild): Yearly temperature continentality is below 300. Summer wetness index is below 0.7, winter wetness index is above 1.
3mo: (warm temperate dry summer mild): Yearly temperature continentality between 300 and 650. Summer wetness index is below 0.7, winter wetness index is above 1.
3mc (warm temperate dry summer continental): Yearly temperature continentality above 650. Summer wetness index is below 0.7, winter wetness index is above 1.
3wh (warm temperate dry winter hypermild): Yearly temperature continentality is below 300. Summer wetness index is above 1, winter wetness index is below 0.7
3wo (warm temperate dry winter mild): Yearly temperature continentality between 300 and 650. Summer wetness index is above 1, winter wetness index is below 0.7
3wc (warm temperate dry winter continental): Yearly temperature continentality above 650. Summer wetness index is above 1, winter wetness index is below 0.7
3s (warm temperate semiarid): Yearly wetness index is between 0.25 and 0.7 and neither summer or winter have wetness index above 1
3d (warm temperate desert): Yearly wetness index less than 0.25
Zone 4 (cool temperate): Yearly biotemperature 6-12°C
At this point I stopped taking into account precipitation seasonality. I don't think it matters as much when the climates are colder.
4h (cool temperate hypermild): Yearly temperature continentality below 300, yearly wetness index above 0.7.
4o (cool temperate oceanic): Yearly temperature continentality between 300 and 650, yearly wetness index above 0.7.
4c (cool temperate continental): Yearly temperature continentality above 650, yearly wetness index above 0.7.
4s (cool temperate semiarid): Yearly wetness index is between 0.25 and 0.7.
4d (cool temperate desert): Yearly wetness index less than 0.25
Zone 5 (boreal): Yearly biotemperature 3-6°C
5h (boreal hypermild): Yearly temperature continentality below 300, yearly wetness index above 0.7.
5o (boreal oceanic): Yearly temperature continentality between 300 and 650, yearly wetness index above 0.7.
5c (boreal continental): Yearly temperature continentality between 650 and 1650, yearly wetness index above 0.7.
5x (boreal extreme continental): Yearly temperature continentality above 1650, yearly wetness index above 0.7.
5d (boreal dry): Yearly wetness index below 0.7. No distinction between semiarid and desert.
Zone 6 (subpolar/subalpine): Yearly biotemperature 1.5-3°C
6h (subpolar/subalpine hypermild): Yearly temperature continentality below 300
6o (subpolar/subalpine mild): Yearly temperature continentality between 300 and 650
6c (subpolar/subalpine continental): Yearly temperature continentality above 650
Zone 7 (icecap): Yearly biotemperature 0-1.5°C
This zone has no subtypes. It is simply marked as just 7.
Cities/places in the climate types:
1r: Singapore, Kisangani, Iquitos, San Juan (Puerto Rico), Lae
1w: Ho Chi Minh City, Dhaka, Darwin, Santa Cruz De La Sierra, Lagos
1s: Merida (Yucatan), Maracaibo, Kano, Bamako, Delhi, Bangkok
1d: Los Mochis, Nouakchott, Khartoum, Riyadh
2f: Houston, Tampa, Porto Alegre, Taipei, Brisbane
2m: Austin, Tunis, Tel Aviv, Adana, Erbil (You may notice a lot of Southern US cities in "dry summer zones." This is because while they receive about the same amount of precipitation year round, the heat and evaporation actually causes the summers to be a lot drier)
2w: Fort Myers, São Paulo, Durban, Hong Kong, Hanoi, Townsville
2s: McAllen-Reynosa, Santiago del Estero, Maputo, Lahore
2d: Phoenix, Lima, Cairo, Baghdad, Coober Pedy
3fh: Quito, Bogotá, Tristan da Cunha, Wabag, Whangarei
3fm: Buenos Aires, Bilbao, Batumi, Sydney, Auckland
3fc: Washington DC, Atlanta, Shanghai, Wuhan, Tokyo, Osaka
3mh: San Francisco, Concepción (Chile), parts of Cape Town, King Island (Tasmania), Ponta Delgada (Azores)
3mo: Sacramento, Santiago, Lisbon, Rome, Casablanca, Adelaide
3mc: Oklahoma City, Redding, Milan, Athens, Gaziantep, Tashkent
3wh: Mexico City, Quetzaltenango, Addis Ababa
3wo: Johannesburg, Kunming
3wc: Almost exclusively found within the Sichuan Basin
3s: Lubbock, San Luis PotosÃ, Neuquen, Zaragoza, Bloemfontein, Shijiazhuang
3d: Bakersfield, Antofagasta, Tehran, AÅŸgabat, Turpan
4h: El Alto, Castro (Chile), Falkland Islands, Stewart Island (NZ)
4o: Seattle, Temuco, London, Paris, Mokhotlong (Lesotho), Christchurch, Thimphu
4c: Toronto, Boston, Chicago, Berlin, Bucharest, Moscow, Van, Shenyang, Pyongyang, Sapporo, Harbin
4s: Denver, Boise, Rio Gallegos, Constanta, Nur-Sultan, Hohhot
4d: Wendover (Utah, USA), Baikonur, Jiuquan
5h: Kerguelen Islands and parts of Tierra Del Fuego
5o: Aleutian Islands, Ushuaia, Reykjavik, Trondheim
5c: Anchorage, Yellowknife, Vaasa, Murmansk, Khanty-Mansiysk, Irkutsk, Ulaanbaatar
5x: Yakutsk, Oymyakon, Neryungri. Fort Yukon, Alaska is on the edge of this climate.
5d: No cities really have this climate, but it definitely exists. The high peaks of the Andes in the Atacama Desert and some high elevation parts of Mongolia, as well as some northern reaches of the Sakha Republic, have this climate.
6h: Exceptionally rare. Some very high parts of the Andes have it
6o: The middle of Iceland.
6c: Iqaluit, Nuuk, Prudhoe Bay, Naryan-Mar, Norilsk, Anadyr
7: Most of Greenland, Antarctica
I also made a raster file of these climates if anyone is interested. You can display it on GIS software.
Sydney and Buenos Aires just don't sit right with Batumi, Auckland and Bilbao. I'd put Melbourne in 3fm instead.
Sydney is on the wetter end of 2s and 2m, and on the drier end of 2f - It fits there better than in 3fm tbh. Same here, our summers have a wet trend but the evaporation rate really makes them drier than what they are (winters are drier and sunnier but the morning dew keeps the grass rather moist, whereas in summer the ground can get pretty dry even after thunderous rainfalls).
But anyway, I really disagree how you take the evaporation rate in account here. The climates of Austin and Tel Aviv have pretty different "genetics" and would be incomparable.
Great job OP! This system classifies downtown Los Angeles as subtropical dry-summer and the LAX airport as warm-temperate semi-arid, which is the same as Koppen-Geiger.
Sydney seems to be on the boundary between warm-temperate and subtropical.
Edit: there seem to be some errors in your list of examples. I calculated Wuhan's winter wetness index to be 0.43
Last edited by psyche_da_mike24; 05-25-2021 at 01:38 AM..
Sydney and Buenos Aires just don't sit right with Batumi, Auckland and Bilbao. I'd put Melbourne in 3fm instead.
Sydney is on the wetter end of 2s and 2m, and on the drier end of 2f - It fits there better than in 3fm tbh. Same here, our summers have a wet trend but the evaporation rate really makes them drier than what they are (winters are drier and sunnier but the morning dew keeps the grass rather moist, whereas in summer the ground can get pretty dry even after thunderous rainfalls).
But anyway, I really disagree how you take the evaporation rate in account here. The climates of Austin and Tel Aviv have pretty different "genetics" and would be incomparable.
I feel like a lot of warm temperate oceanic climates are shown as dry summer on this map, especially ones that receive a bit lower annual precipitation. Melbourne appears to be 3s on my map due to its significantly low precipitation levels. If I were to make this map again, I would lower the threshold for dry summer climates to 0.5 instead of 0.7. I feel like there wouldn't be as many oddities occuring if that was the case. I like the idea of a lot of Texas being "dry summer." I don't know why, it just feels nice. A lot of the vegetation of tat part of Texas seems to be scrubby and chapparal-esque but I understand how it would differ from the Mediterranean climate. I just liked the system of using PET rate because it made a lot more sense to me than Köppen's weird aridity index system of like... multiplying the temperature by 20 and then adding a weird arbitrary number based on how much rain falls in summer.
I recommend keeping the summer and winter wetness calculations for climates like Delhi that are "tropical" in terms of biotemperature, but still have significant seasonal temperature variation. I feel like there should be some way to single out hotter subtropical/outer tropical climates that have marked temperature differences between the "dry" and "wet" seasons.
I feel like a lot of warm temperate oceanic climates are shown as dry summer on this map, especially ones that receive a bit lower annual precipitation. Melbourne appears to be 3s on my map due to its significantly low precipitation levels. If I were to make this map again, I would lower the threshold for dry summer climates to 0.5 instead of 0.7. I feel like there wouldn't be as many oddities occuring if that was the case. I like the idea of a lot of Texas being "dry summer." I don't know why, it just feels nice. A lot of the vegetation of tat part of Texas seems to be scrubby and chapparal-esque but I understand how it would differ from the Mediterranean climate. I just liked the system of using PET rate because it made a lot more sense to me than Köppen's weird aridity index system of like... multiplying the temperature by 20 and then adding a weird arbitrary number based on how much rain falls in summer.
Not going to blame you here and I see where you're coming from - Because I feel that way when it comes to Sydney's vegetation. Like most of Australia's vegetation, Sydney's vegetation community is also rather scrubby and dry-ish even though the region categorically falls under the "temperate broadleaf and mixed forests" - Eastern USA and North-western Europe fall within that biome as well and their vegetation looks nothing like ours.
I've always thought, and have argued, that you can have a classic Mediterranean climate but lack the so-called "Mediterranean vegetation", and vice versa - I mean, there are places with "Mediterranean vegetation" that have oceanic, steppe and even savannah climates. And what the hell does "Mediterranean vegetation" even mean? How come there isn't "oceanic vegetation", "humid subtropical vegetation", "tropical monsoon vegetation"? It just doesn't make sense to me. Why conflate climate classes with vegetation?
Yes, whilst Texas is climatically Cfa, its vegetation is more like the Mediterranean/semi-arid regions in California and West Asia. So that's why I think we should really ditch the "Mediterranean" term as a vegetation biome, and rather use something like "sclerophyll" (what the Australian systems use). Because many non-Mediterranean climates have "Mediterranean vegetation" and yet don't have the dry summers and wet winters. Because there are even a few regions, such as those in south-eastern Europe, that have deciduous or "temperate broadleaf" vegetation but are climatically "Mediterranean". So climate classification =/ vegetation.
So yeah, I get where you're coming from.
Spoiler
The rather inaccurately broad temperate broadleaf & mixed forests zone:
Typical vegetation in Sydney (looks very English, Irish, Dutch, or perhaps maybe like some urban woodland in Japan or New York?...NOT!):
Location: Live:Downtown Phoenix, AZ/Work:Greater Los Angeles, CA
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Quote:
Originally Posted by Ethereal
Not going to blame you here and I see where you're coming from - Because I feel that way when it comes to Sydney's vegetation. Like most of Australia's vegetation, Sydney's vegetation community is also rather scrubby and dry-ish even though the region categorically falls under the "temperate broadleaf and mixed forests" - Eastern USA and North-western Europe fall within that biome as well and their vegetation looks nothing like ours.
I've always thought, and have argued, that you can have a classic Mediterranean climate but lack the so-called "Mediterranean vegetation", and vice versa - I mean, there are places with "Mediterranean vegetation" that have oceanic, steppe and even savannah climates. And what the hell does "Mediterranean vegetation" even mean? How come there isn't "oceanic vegetation", "humid subtropical vegetation", "tropical monsoon vegetation"? It just doesn't make sense to me. Why conflate climate classes with vegetation?
Yes, whilst Texas is climatically Cfa, its vegetation is more like the Mediterranean/semi-arid regions in California and West Asia. So that's why I think we should really ditch the "Mediterranean" term as a vegetation biome, and rather use something like "sclerophyll" (what the Australian systems use). Because many non-Mediterranean climates have "Mediterranean vegetation" and yet don't have the dry summers and wet winters. Because there are even a few regions, such as those in south-eastern Europe, that have deciduous or "temperate broadleaf" vegetation but are climatically "Mediterranean". So climate classification =/ vegetation.
So yeah, I get where you're coming from.
Spoiler
The rather inaccurately broad temperate broadleaf & mixed forests zone:
Typical vegetation in Sydney (looks very English, Irish, Dutch, or perhaps maybe like some urban woodland in Japan or New York?...NOT!):
The only two trees that I exclusively associate with Mediterranean climates are Chaparral and Italian Cypress, though those also grow in semi arid climates (and can be planted and thrive in desert climates, as is seen in the cities in lowland Arizona and the desert cities in California)
Not going to blame you here and I see where you're coming from - Because I feel that way when it comes to Sydney's vegetation. Like most of Australia's vegetation, Sydney's vegetation community is also rather scrubby and dry-ish even though the region categorically falls under the "temperate broadleaf and mixed forests" - Eastern USA and North-western Europe fall within that biome as well and their vegetation looks nothing like ours.
I've always thought, and have argued, that you can have a classic Mediterranean climate but lack the so-called "Mediterranean vegetation", and vice versa - I mean, there are places with "Mediterranean vegetation" that have oceanic, steppe and even savannah climates. And what the hell does "Mediterranean vegetation" even mean? How come there isn't "oceanic vegetation", "humid subtropical vegetation", "tropical monsoon vegetation"? It just doesn't make sense to me. Why conflate climate classes with vegetation?
Yes, whilst Texas is climatically Cfa, its vegetation is more like the Mediterranean/semi-arid regions in California and West Asia. So that's why I think we should really ditch the "Mediterranean" term as a vegetation biome, and rather use something like "sclerophyll" (what the Australian systems use). Because many non-Mediterranean climates have "Mediterranean vegetation" and yet don't have the dry summers and wet winters. Because there are even a few regions, such as those in south-eastern Europe, that have deciduous or "temperate broadleaf" vegetation but are climatically "Mediterranean". So climate classification =/ vegetation.
So yeah, I get where you're coming from.
Spoiler
The rather inaccurately broad temperate broadleaf & mixed forests zone:
Typical vegetation in Sydney (looks very English, Irish, Dutch, or perhaps maybe like some urban woodland in Japan or New York?...NOT!):
Yes. Central Texas is a transitional climate between humid subtropical and semi arid. It’s a weird area... dry, limestone hills covered in scrubby plants and short, twisty oaks. Lots of cacti and other succulents, but also plentiful wildflowers in the spring. Mediterranean plants do extremely well here in Austin due to the rocky, alkaline soil and hot, dry summers. Yes, summer rainfall is above the threshold to be considered Mediterranean, but most of that rainfall comes in one or two storms. The rest of the time it is dry, brown, and dusty. Austin or San Antonio in the summer are *nothing* like cities east of the area, not even Houston which isn’t far away. It’s so Mediterranean-like that even vineyards have become a big thing in the hill country region. The biggest issue we have is that we can get really hard freezes every few years that Mediterranean plants do not like.
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