WIP (sort of tutorial to be) : Climates, applying Geoff's Cookbook at detail (some)

[Pixie]

Thanks for your time, Azelor. You've pointed out some important stuff, namely, that I am ignoring the interaction between temperature and "wetness" when considering how dry is a climate. I think the desert/steppe/continental "gradient" will have to be a little reviewed.

The point of this whole system, however, is to skip numbers - this is not because of laziness, but because there are so many "educated guesses" and approximations when it comes to a fictional planet-system that the uncertainty of any number is absurd. I mean, what's the point of saying a given place has a mean temperature of 25 ºC if the margin for such figure is.. say.. 30%. So, that's the rationale behind a fully graphical method, just to explain myself. Of course, you can throw a guess about what exactly "Very Hot", "Hot" or whatever means. I can agree with your guess without second thoughts.
I also want to make this tutorial easy enough for those without a science background - as much as that is possible - and that is why I am trying to define clear and easy to follow rules. Even to the point where some accuracy is lost. I'm not sure how this balance will work out.

Now, as for your valuable comments.

BSh and BSk: small detail but it's S and not s, otherwise it mean summer dry
these two climates can have a rainy season, some places could receive up to around 200mm of rain in a month because they are subject to the monsoon (mostly the hot one). Large parts of the steppes in Africa and Eastern Asia are affected. Examples include Niamey and Hohhot.

So, I will probably have to review some of the combinations. Say, if a region is Very Hot/Hot in a season and Low in wetness, that roughly equates to "Dry" - and it would still be desert. Do you agree with this generalization?

BSk : is usually found at higher altitude than the hot desert

Dont forget that : (I know it's pretty complicated!)

B. Dry climate: Annual evaporation is greater than precipitation (also called potential evotraspiration). To determine whether a location has an arid climate, the precipitation threshold must first be determined. The threshold value (in millimetres) is determined as:
• If less than 30% of annual precipitation occurs in the summer : Annual precipitation (mm) < 20 × average annual temperature (°C)
• If more than 70 % of annual precipitation occurs in the summer: Annual precipitation (mm) < 20 × average annual temperature + 280
• Else : Annual precipitation (mm) < 20 × average annual temperature + 140

o If annual precipitation is < 50 % of the threshold = BW: desert climate
o If annual precipitation is between 50 and 100 % = BS: steppe climate

Altitude is already factored in as one determines wetness maps and temperature maps, so Cold Steppes should appear naturally when a Hot Steppe region is in altitude (and it does in my tests). As for the numbers, I am aware of those, but as I explained I don't think I can bring formulas to this system (Geoff's Cookbook avoided it too).

So the steppe climates can be more or less rainy if the evaporation is very high too. The same principle stand for colder climates too. They receive much less rain than hot climates but are still considered wet because the evaporation is much lower.

As I said, I'll review where some of the combinations fall into, namely between cold steppe and continental (C's and D's) and between hot steppe and mediterranean.

(detail) Also, according to the classification, it's possible to have cold winters in BSh as long as the average yearly temp are high enough. Rare but possible

(detail) BWn: it's an additional class for desert near water that have a small temperature variation like Namibia. I was considering incorporating it

Thanks for these details. I didn't know BWn classification. As for the detail about the BSh, if we don't mention it in "the rules", a piece of hot steppe will be classified as cold steppe, if we mention it, the rule gets more complicated... a choice affecting balance between accuracy and friendliness...

Csb: monthly temperature never go over 22, so it's not hot and not cold either because it never go below 0 (monthly)
I just like to specify that Csc form usually at higher altitudes at it's not very common

This was definitely a choice I made towards friendliness. Merging Csb and Csc allowed for Cold winters. In my tests this covered highlands close to Mediterranean proper (Csa) more than areas immediately poleward of Csa, but it might be a peculiarity of the continent I used. That's why I will have to try this system in different continents.

Cwb/Cwc: monthly temperature never go over 22, so it's not hot and it's even colder for Cwc, they are located at higher altitudes

I get your point but, the thing is, how would you classify a region with Hot summers (over 22) and Cold winters, with sufficient wetness (that's "moderate" or above in the current rules). However, I see Hot+VeryWet Summers with Cold/LowRain Winters falling a bit awkwardly into Cwb - can you find a better fit?

D climates: if I have the temperature right for the extreme cold, it should only be applied with : Dfd, Dwd, Dsd and the other colder climates. I tried to find other climates in the D group with winter months under -38 but I could not.

So, the consequence of this is that all regions with an Extreme Cold temperature should strictly be Taiga or Tundra?

Dfa,Dfb: you inversed the summer and winter precipitations.

Thanks... fixed! (wish all fixes were these simple

As I said, thank you for the help. There's a few questions in the middle of my replies, did you spot them? As for temperature and rain charts, you can see them in a previous post, I have the four side by side when explaining how to "find climate zones".

[Azélor]

You’re probably right, we are just amateur for the most part so using real numbers will only make the process more complicated for a little gain in precision. And most people won’t notice it.
Obviously, if I’m trying to make it simpler, I’m heading in the wrong direction !

So, I will probably have to review some of the combinations. Say, if a region is Very Hot/Hot in a season and Low in wetness, that roughly equates to "Dry" - and it would still be desert. Do you agree with this generalization?

I’m not sure I understand the question. My main point was to say that in Koppen classification ‘’S’’ and ‘’s’’ are two different things.

S: second letter that indicates a steppe and only usable with first letter B
s: also second letter but mean that the summer is dry. Maybe it’s possible to use it with B but for some reasons, it does not apply to deserts BW (because it rarely rain anyway) or steppes BS.

Very hot and dry season = desert or steppe

Since monsoon only occurs in summer the very hot season, it’s impossible to have a monsoonal climate with a hot and dry summer but wet winter. The only that comes to mind is AS but the dry season is only considered dry because the wet season is really rainy. So it’s not that dry.

So it’s either a hot desert or it could also be a hot semi-arid. He does not have to be subject to the monsoon. And if it’s not affected by monsoon, the wet season is also the coldest.
So it means there are two types of hot arid climates, with different precipitation pattern, nice…

So, the consequence of this is that all regions with an Extreme Cold temperature should strictly be Taiga or Tundra?

I guess so. Extreme would not be extreme if it applied to a large part of the world.
This is about the coldest I've found in Dfc, Dwc, Dsc Krasnoyarsk Krai - Wikipedia, the free encyclopedia
Don't forget that the number are based on the monthly average. For example, it's possible to have a temperature of -50 in Manitoba (Dfb) or Mongolia but that's way below their average.

I get your point but, the thing is, how would you classify a region with Hot summers (over 22) and Cold winters, with sufficient wetness (that's "moderate" or above in the current rules). However, I see Hot+VeryWet Summers with Cold/LowRain Winters falling a bit awkwardly into Cwb - can you find a better fit?

Well to start of, there is probably just one place on Earth with a Cwc climate based on the wiki map. Can you find it just by looking at the map ?
It's possible to have it cover a larger area in a fantasy map but it won't be much. But you question is how to classify this climate ? :

Summer: Hot, very wet
Winter : Cold, dry

Dwa maybe ? It's affected by the monsoon but I'm not sure it's wet enough

As for temperature and rain charts, you can see them in a previous post, I have the four side by side when explaining how to "find climate zones".

Really? I mean the 2 central parts are really dry. But I can't say if you did something wrong with the precipitation pattern because that part is really hard for me.