| Classification | P/ETP | Precipitation (mm) |
| Hiper Arid | <0.05 <200 | |
| Arid | 0.05 - 0.20 | <200 (winter) o <400 (summer) |
| Semi-arid | 0.20 - 0.50 | 200 - 500 (winter) o 400 - 600 (summer) |
| dry subhumid | 0.50 - 0.65 | 500 - 700 (winter) o 600 - 800 (summer) |
| Subhumid | 0.65 - 1.00 | |
| humid | >1.00 |