| PDSI | 等级 | PDSI | 等级 |
| ≥4.00 | 极度湿润 | −1.00~−1.99 | 轻微干旱 |
| 3.00~3.99 | 严重湿润 | −2.00~−2.99 | 中度干旱 |
| 2.00~2.99 | 中度湿润 | −3.00~−3.99 | 严重干旱 |
| 1.00~1.99 | 轻微湿润 | ≤4.00 | 极度干旱 |
| 0.99~−0.99 | 正常 |
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