Zanzibar records about 1650mm of rain across roughly 110 wet days a year, which is a 30% chance on an average day. April is the wettest month at 320mm (19% of the annual total) and July the driest at 30mm. Local rain type: monsoon. Zanzibar has two rainy seasons: the "long rains" (March-May) can be torrential, while the "short rains" (November-December) are manageable. June through October is reliably dry — no umbrella needed.
Chance of rain on an average day: 30%
Rainfall climatology for Zanzibar. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1650mm |
| Rain days per year | 110 |
| Odds on an average day | 30% |
| Wettest month | April — 320mm over 24 days |
| Driest month | July — 30mm over 2 days |
| Rain type | monsoon |
| Best dry window | June through October is the dry season with warm temperatures, low humidity, and virtually no rain. |
| Worst rain window | April is the wettest month with potential for all-day tropical downpours that can flood unpaved roads. |
April delivers 967% more rain than July (320mm vs 30mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 19% of the annual total, so rain in Zanzibar is spread through the year — there is no season you can rely on being dry.
Zanzibar rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 24 days in April against 2 in July — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 60mm | 5 | 17% | 32°C |
| February | 50mm | 4 | 13% | 32°C |
| March | 130mm | 10 | 33% | 32°C |
| April | 320mm | 24 | 80% | 31°C |
| May | 280mm | 21 | 70% | 30°C |
| June | 50mm | 4 | 13% | 29°C |
| July | 30mm | 2 | 7% | 29°C |
| August | 30mm | 2 | 7% | 29°C |
| September | 40mm | 3 | 10% | 29°C |
| October | 90mm | 7 | 23% | 30°C |
| November | 200mm | 15 | 50% | 31°C |
| December | 170mm | 13 | 43% | 32°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Zanzibar we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Zanzibar records rain on roughly 110 days a year — about a 30% chance on any given day — totalling around 1650mm.
April, with about 320mm over 24 rain days. That is 19% of the entire year's rainfall in a single month.
July is the driest month at 30mm across roughly 2 days. June through October is the dry season with warm temperatures, low humidity, and virtually no rain.
Zanzibar has two rainy seasons: the "long rains" (March-May) can be torrential, while the "short rains" (November-December) are manageable. June through October is reliably dry — no umbrella needed.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.