When to go?
Zanzibar Islands is only a few degrees south of the equator so there is little seasonal variation in temperature. The average maximum is in the 26 C during the winter months, May to September, and in the 30 C from November through to April.Rainfall varies a lot in April and May are the monsoon months and the wettest, with up to 15 inches of rain per month, and many hotels close until mid-June. The “short rains” fall in November and early December, but should not spoil a holiday: you would expect tropical showers, rather than continuous rain.
The driest periods are from June to late October, with relatively low humidity and refreshing breezes, and mid-December to February. In January, Zanzibar is hot and, with the approach of the monsoon, it becomes more humid place.