Index value

Classification

Probability

Occurrence

SPI ≥ 2.00

Extremely wet

0.977 - 1.000

2.3%

1.50 ≤ SPI < 2.00

Very wet

0.933 - 0.977

4.4%

1.00 ≤ SPI < 1.50

Moderate wet

0.841 - 0.933

9.2%

−1.00 ≤ SPI < 1.00

Near normal

0.159 - 0.841

68.2%

−1.50 ≤ SPI < −1.00

Moderately drought

0.067 - 0.159

9.2%

−2.00 ≤ SPI < −1.50

Severe drought

0.023 - 0.067

4.4%

SPI < −2.00

Extremely drought

0.000 - 0.023

2.3%