Temporal Description of Annual Temperature and Rainfall in the Bawku Area of Ghana

Table 2

SPI values.

SPI results	Interpretation	Probability of occurrence	Severity of event
≥2.0	Extremely wet	2.3	1 in 50 years
1.5 to 1.99	Very wet	4.4	1 in 20 years
1.0 to 1.49	Moderately wet	9.2	1 in 10 years
0.0 to 0.99	Mildly wet (NN)	34.1	1 in 03 years
0.0 to −0.99	Mildly dry (NN)	34.1	1 in 03 years
−1.0 to −1.49	Moderately dry	9.2	1 in 10 years
−1.5 to −1.99	Very dry	4.4	1 in 20 years
≤−2.0 and less	Extremely dry	2.3	1 in 50 years

NB: “NN” means near normal. Source: [39, 42].