Table 1 Overview of the Köppen-Geiger climate classes including the defining criteria.

From: High-resolution (1 km) Köppen-Geiger maps for 1901–2099 based on constrained CMIP6 projections

Letter symbol

 

1st

2nd

3rd

Description

Criteriona

A

  

Tropical

Not (B) & Tcold ≥ 18

f

 

 - Rainforest

Pdry ≥ 60

m

 

 - Monsoon

Not (Af) & Pdry ≥ 100-MAP/25

w

 

 - Savannah

Not (Af) & Pdry < 100-MAP/25

B

  

Arid

MAP < 10×Pthreshold

W

 

 - Desert

MAP < 5×Pthreshold

S

 

 - Steppe

MAP ≥ 5 × Pthreshold

 

h

  - Hot

MAT ≥ 18

 

k

  - Cold

MAT < 18

C

  

Temperate

Not (B) & Thot > 10 & 0 < Tcold < 18

s

 

 - Dry summer

Psdry < 40 & Psdry < Pwwet/3

w

 

 - Dry winter

Pwdry < Pswet/10

f

 

 - Without dry season

Not (Cs) or (Cw)

 

a

  - Hot summer

Thot ≥ 22

 

b

  - Warm summer

Not (a) & Tmon10 ≥ 4

 

c

  - Cold summer

Not (a or b) & 1 ≤ Tmon10 < 4

D

  

Cold

Not (B) & Thot > 10 & Tcold ≤ 0

s

 

 - Dry summer

Psdry < 40 & Psdry < Pwwet/3

w

 

 - Dry winter

Pwdry < Pswet/10

f

 

 - Without dry season

Not (Ds) or (Dw)

 

a

  - Hot summer

Thot ≥ 22

 

b

  - Warm summer

Not (a) & Tmon10 ≥ 4

 

c

  - Cold summer

Not (a, b, or d)

 

d

  - Very cold winter

Not (a or b) & Tcold < −38

E

  

Polar

Not (B) & Thot ≤ 10

T

 

 - Tundra

Thot > 0

F

 

 - Frost

Thot ≤ 0

  1. Adapted from Peel et al.39.
  2. aVariable definitions: MAT = mean annual air temperature (°C); Tcold = the air temperature of the coldest month (°C); Thot = the air temperature of the warmest month (°C); T mon10 = the number of months with air temperature > 10 °C (unitless); MAP = mean annual precipitation (mm y−1); Pdry = precipitation in the driest month (mm month−1); Psdry = precipitation in the driest month in summer (mm month−1); Pwdry = precipitation in the driest month in winter (mm month−1); Pswet = precipitation in the wettest month in summer (mm month−1); Pwwet = precipitation in the wettest month in winter (mm month−1); Pthreshold = 2×MAT if > 70% of precipitation falls in winter, Pthreshold = 2×MAT + 28 if > 70% of precipitation falls in summer, otherwise Pthreshold = 2×MAT + 14. Summer (winter) is the six-month period that is warmer (colder) between April–September and October–March.
Back to article page