Climatically the best period ever goes from November to March, but it is also good from August to October. The rainy season usually runs from mid-April to mid-July, the worst months are May and June.
At Watamu it’s hot all year round, the seasonal variations in temperature are limited, with a warm season from November to April when the daily temperatures are around 31/33 degrees and at night 23/25 degrees, and a cool season from June to September, where by day they are around 27/28 degrees and at night 22 degrees.
The sea at Watamu is warm enough to bathe all year round, the temperature varies from 25 degrees in August to 28/30 degrees from November and April.
Watamu is located near the equator, so it is protected from tropical cyclones, like the rest of the Kenyan coast.