Koppen Classification Scheme

 

Primary Letter (upper case) based on temperature characteristics (except B):

A - Tropical All Year
B - Arid
C - Temperature Seasons - mild winters
D - Temperature Seasons - severe winters
E - Cold All Year

 

Secondary Letter (lower case) based on precipitation characteristics:

f - precipitation evenly distributed throughout the year
w - wet and dry seasons
m - monsoons
s - dry summer

 

Third Letter based on severity of winter:

a - short, mild winters, long warm summers
b
c
d - long, cold winters, short, cool summers

World Map of Koppen Climate Classification