| Standardized Precipitation Index | Condition |
| ≥2.00 | Extremely Humid |
| 1.50 a 1.99 | Severely Humid |
| 1.00 a 1.49 | Moderately Humid |
| 0.00 a 0.99 | Initial Humidity |
| 0.00 a −0.99 | Initial Dry |
| −1.00 a −1.49 | Moderately Dry |
| −1.50 a −1.99 | Severely Dry |
| ≤−2.00 | Extremely Dry |