Onset, Peak, and Recession of Rainfall

The normal onset of rainy season is on the later part of May (21-31), increases almost evenly until the peak is reached in August and recedes in the later part of September (21-30).

Onset, termination/recession, length of rainy season and total rainfall per year (1976-2020).

Onset- accumulated rainfall of 200 mm after April 1 (Morris and Zandstra, 1979)
Recession - backward accumulation of 300 mm starting March 31 (Morris and Zandstra, 1979)
Note: under % Normal 0- 40 - way below normal 41-80 - near normal 81-120 - Normal>120 - above normal