Code

Class

PDSI range

D4

extreme drought

PDSI < −4

D3

severe drought

−4

D2

moderate drought

−3 < PDSI ≤ −2

D1

mild drought

−2 < PDSI ≤ −1

N

near normal

−1 < PDSI ≤ 1

W1

mild wet

1 ≤ PDSI < 2

W2

moderate wet

2 ≤ PDSI < 3

W3

very wet

3 ≤ PDS < 4

W4

extremely wet

4 ≤ PDSI