Table 1. Description of the Koppen climate symbols and defining criteria (Peel et al., 2007).
| 1st | 2nd | 3rd | Description | Criteria* |
|---|---|---|---|---|
| A | Tropical | 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 ≥ 10 × Pthreshold | ||
| h | - Hot | MAT ≥ 18 | ||
| k | - Cold | MAT < 18 | ||
| C | Temperate | Thot > 10 & 0 < Tcold < 18 | ||
| s | - Dry Summer | Psdry < 40 & Psdry < Pwwet/3 | ||
| w | - Dry Winter | Psdry < Pwwet/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 | Thot > 10 & Tcold ≤ 0 | ||
| s | - Dry Summer | Psdry < 40 & Psdry < Pwwet/3 | ||
| w | - Dry Winter | Psdry < Pwwet/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 | Thot < 10 | ||
| T | - Tundra | Thot > 0 | ||
| F | - Frost | Thot ≤ 0 |
*The first letters (A to E) refer to the broad climate types. The second letters (f, m, w/W and s/S) are the subsequent precipitation conditions. Because no precipitation differentiations are given for the polar climates (E), the letters T and F are defined for the temperature conditions. The third letters are temperature classifications (h) and (k) for the arid climates (B) and (a) to (d) for the warm temperate and snow climates (C) and (D). MAP = mean annual precipitation, MAT = mean annual temperature, Thot = temperature of the hottest month, Tcold = temperature of the coldest month, Tmon10 = number of months where the temperature is above 10 °C, Pdry = precipitation of the driest month, Psdry = precipitation of the driest month in summer, Pwdry = precipitation of the driest month in winter, Pswet = precipitation of the wettest month in summer, Pwwet = precipitation of the wettest month in winter, Pthreshold = varies according to the following rules (if 70% of the MAP occurs in winter, then Pthreshold = 2 × MAT; if 70% of the MAP occurs in summer, then Pthreshold = 2 × MAT + 28, otherwise Pthreshold = 2 × MAT + 14). Summer (winter) is defined as the warmer (cooler) six month period of ONDJFM and AMJJAS.