SPI-Based Spatiotemporal Drought over Sri Lanka

Table 2

Dryness/wetness category according to SPI value [6].

SPI value	Class
SPI ≥ 2.00	Extremely wet
1.50 ≤ SPI < 2.00	Severely wet
1.00 ≤ SPI < 1.50	Moderately wet
0.00 ≤ SPI < 1.00	Mildly wet
−1.00 ≤ SPI < 0.00	Mild drought
−1.50 ≤ SPI < −1.00	Moderate drought
−2.00 ≤ SPI < −1.50	Severe drought
SPI < −2.00	Extreme drought