Bagamoyo has a tropical coastal climate — hot all year, with two rainy seasons. The long rains (Masika) run from March to May, the short rains (Vuli) from October to December. Between them, June to October is the cool dry season — pleasant, sunny, with sea breezes — and the best time to visit.
The Bagamoyo Festival of Arts and Culture in late September is the cultural high point of the year, with drumming, dance, theatre, and storytelling for a full week at the College of Arts. The town fills up; book ahead. The October to December short rains rarely last more than an hour at a time and need not put you off a visit — the bush turns green and the bird life is at its best.
Avoid the long March–May rains: the roads outside town flood, the heat is heavy, and the mosquito season is at its worst.