SPI values | Classification |
2.00> | Extremely wet |
1.50 - 1.99 | Very wet |
1.00 - 1.49 | Moderately wet |
0.99 - −0.99 | Near normal |
−1.00 - −1.49 | Moderately dry |
−1.50 - −1.99 | Severely dry |
−2.00< | Extremely dry |