What is the best month to visit Zanzibar?

For reliable sun with a sea breeze, July to September. For the warmest sea and calmest water, January to February. Both are excellent; the difference is wind and heat, not whether you will get a good holiday.

When is the rainy season in Zanzibar?

There are two. The long rains run mid-March to May (heavy, the wettest stretch and when some places close). The short rains fall in November, usually brief afternoon showers that pass.

When is the best time to kitesurf in Zanzibar?

The Kusi season, roughly June to September, gives the most consistent wind on the east coast (Paje, Jambiani, Michamvi). A second, shorter window comes in January during Kaskazi.

When is the best diving and snorkelling?

December to February, when the wind drops, the sea flattens and visibility is at its best. October is also strong. Avoid the long rains for underwater clarity.

Is the seaweed (tide) a problem on the east coast?

The east coast has a big tidal range, so swimming is tide-led rather than all-day at some beaches. Seaweed farming is most visible in the dry season. Pick a hotel with a tidal pool or pool if all-day swimming matters to you.

Does Ramadan affect a Zanzibar trip?

Some local restaurants reduce daytime hours and the pace slows, but beach hotels run normally. Dates move each year, so check before booking if it overlaps your trip.

Zanzibar: When to Go (Seasons, Wind, Rains)

Zanzibar runs on two monsoon winds, not four seasons. Learn those two names and the rest of the calendar makes sense.

The two seasons that actually matter

Kusi is the south-east monsoon, roughly June to October. It is the cooler, drier half of the year: daytime around 27-29C, low humidity, bright skies, and a steady wind off the sea that the whole east coast is built around. Nights can feel genuinely fresh by Zanzibar standards.

Kaskazi is the north-east monsoon, roughly December to February. This is the hot season: 31-33C, higher humidity, lighter wind, glassy mornings and very warm water. It is the classic postcard Zanzibar and the best stretch for getting in the sea.

Between and around those two sit the rains, and they are not equal.

The two rains: which one to avoid

The long rains (Masika) run from mid-March through May. This is the wettest part of the year by a long way: heavy downpours, grey stretches, high humidity, and the time when a fair number of smaller hotels and dive centres close to do maintenance. I would not plan a first Zanzibar trip into April. If you do come in this window you will get cheaper rates and empty beaches, but you are gambling on the weather, and in a bad year you lose.

The short rains (Vuli) fall in November, sometimes nudging into early December. These are different in character: short, sharp afternoon showers that clear within an hour or two, with plenty of sun around them. November is genuinely underrated. Prices are still soft, the islands are green, and the rain rarely wrecks a day.

What to skip: do not book mid-March to May expecting to “risk it for the savings” unless you are relaxed about losing days indoors. The long rains are the one part of the calendar I steer people away from.

Wind: what the locals read each morning

Here is the part the brochures skip. On the east coast, where I am, the wind is the daily headline, and it flips with the season.

During Kusi (June-September especially), that south-east wind is reliable and strong. Stand on Paje or Michamvi beach mid-morning and you will see why this coast became an East African kite capital. It is brilliant for kitesurfing and windsurfing, lively for sailing, and it keeps the air comfortable even when the sun is hard. The trade-off: the sea surface is choppier, and on the breeziest afternoons a beach lounger needs a windbreak.

During Kaskazi (December-February), the wind backs off. Mornings go glassy, the water warms up, and snorkelling and diving come into their own. That same calm is why January and February are the sweet spot for anyone who wants the sea flat and clear rather than racing across it.

A first-hand note: on most Kusi mornings I can tell roughly how the afternoon will go just from the sound of the palms before breakfast. Soft rustle means a gentle day on the water; a steady roar by 9am means the kiters will be out by lunch and the loungers will want shelter.

Pick your season by what you came to do

Kitesurfing / windsurfing: June-September (Kusi), with a shorter reliable window in January (Kaskazi). These are the two wind seasons; the months in between are hit-or-miss.
Diving and snorkelling: December-February for the calmest water and best visibility; October is also very good as Kusi fades.
Beach, swimming, honeymoon calm: December-February for warm, gentle sea. Remember the east coast is tidal, so check whether your hotel has a tidal pool or pool for all-day swimming.
Cooler, active sightseeing (Stone Town, spice tours, walking): June-September, when the heat and humidity are at their most bearable.
Value and green islands: November or early December (short rains), and the shoulder of late October.

A note on tides and the east coast

Wherever you stay on the east coast, expect a real tidal rhythm: the sea pulls a long way out and comes back in. It is not a flaw, it is the character of this side of the island, and it gives you those vast mirror-flat lagoons at low tide. But it does mean “swim whenever you like” is not automatic on every beach. If you want guaranteed water at any hour, choose accommodation with a pool or a built tidal pool, and check tide timings for your dates.

If you are still weighing where on the island to base yourself, read our Zanzibar east coast guide for how the beaches differ by tide and wind. Planning the wider trip too? Pair this with our Tanzania when to go guide so your safari and beach weeks line up.