Temperatures are quite consistent across all seasons ranging from the high 20‘s to the mid 30‘s throughout the year. Zanzibar’s weather pattern follows that of Tanzania very closely – though you’ll note that it is a little more humid. Generally the main rainy season is between March and May. The humidity at this time is high and daily temperatures reach the low 30°s but no higher.
The dry season is Zanzibar is long and rainfall is unusual – it is between June and October. Temperatures vary hugely with altitude and location, but you’ll mostly always be under clear skies and sunny weather. During November and December there’s another rainy season: referred to as the ‘short rains’. These are much lighter than the main rains and less reliable – so travel is still possible at this time but you may bare witness to the odd rainstorm.