Zanzibar weather by month

How to read the Zanzibar weather table

The table gives monthly averages for Stone Town: the daytime high and night-time low and the total rainfall come from the ERA5 climate reanalysis for 2015–2024, and the sea surface temperature from 2022–2025 data. They describe a typical month, not a forecast: a single April can be drier than average, and even August has the odd shower.

As a rule of thumb, months with less than about 60 mm of rain have mostly dry days. Each month has its own page with more detail, such as Zanzibar in April or Zanzibar in August, and our guide to the best time to visit Zanzibar puts the numbers together with prices, wind and festivals.

Zanzibar temperatures by month and the differences between coasts

The hot season runs from December to March, with highs of 30–32 °C and nights of 25–26 °C. The coolest months are July to September, with highs of 27–28 °C and lows around 23 °C. The gap between day and night is small, so evenings are warm all year.

The island is small and flat, so temperatures are similar everywhere; the real differences are wind and tide. The east coast around Paje, Jambiani and Michamvi faces the open ocean and the trade winds, so it feels fresher and breezier, especially from June to September, while Stone Town on the sheltered west coast can feel sticky. In the north, Nungwi and Kendwa have a small tidal range, while the east-coast lagoons empty at low tide: see Zanzibar's beaches and the tide times.

Humidity, UV and the sun

Zanzibar is humid all year, most noticeably in the hot, wet months from March to May, so it often feels hotter than the thermometer says. Being close to the equator, the midday sun is intense in every season and the UV index is high even on cloudy days. Use a high-factor reef-safe sunscreen, wear a hat, drink plenty of water and plan walks in Stone Town for the morning or late afternoon.

The rains: short showers or all-day rain?

Most rain on Zanzibar falls in short, heavy tropical showers, after which the sun comes back. That is typical of the short rains in November and December and of the occasional shower in the dry months. December still averages about 100 mm, mostly in this kind of shower; see Zanzibar in December and, for the festive season, our guide to Christmas and New Year in Zanzibar.

The long rains of April and May are different: rain can last for hours, grey days are common, and April averages about 370 mm, roughly nine times as much as August. Roads to the coasts can flood and some beach hotels close for the season.

Zanzibar water temperature year round

The sea is warm enough for swimming in every month. It is at its warmest, 29–30 °C, from December to March, and at its coolest, about 26 °C, in August. Most people snorkel without a wetsuit; in July to September a rash vest or thin wetsuit keeps you comfortable on long snorkelling trips or dives.

Forecast Zanzibar: where to check

The official source is the Tanzania Meteorological Authority (TMA) at meteo.go.tz, which publishes forecasts, warnings and seasonal outlooks for the whole country, including Zanzibar; much of the site is in Swahili. General weather apps are fine for temperature and rain probability, but read the rain icon with care: a high chance of rain often means a passing shower. For boat trips and kitesurfing, check a wind forecast and the tides as well.