State

Description

Criterion

Probability (%)

0

Non-drought

SDI ≥ 0.0

50.0

1

Mild drought

−1.0 ≤ SDI < 0.0

34.1

2

Moderate drought

−1.5 ≤ SDI < −1.0

9.2

3

Severe drought

−2.0 ≤ SDI < −1.5

4.4

4

Extremely drought

SDI < −2.0

2.3