Planning

Best time to visit Tanzania: rains, the migration, Kilimanjaro and Zanzibar month by month

When the long and short rains fall, where the wildebeest usually are each month, and the drier windows for climbing Kilimanjaro and for Zanzibar beaches. A month-by-month planner built on Tanzania Meteorological Authority outlooks.

Written by: The Africa Bound Tours team in Arusha
Updated: 28 October 2026

The short answer

For most trips, June to September is the easiest time to visit Tanzania, because it falls between the two rainy seasons. In the north, the long rains (Masika) usually run from March to May and the short rains (Vuli) from October to December. January and February are the other dry gap, and they are typically when wildebeest calve in the southern Serengeti.

When are the rainy seasons in Tanzania?

Northern Tanzania gets two rainy seasons a year. The Tanzania Meteorological Authority (TMA) calls the long rains Masika and puts them between March and May over the areas with two rainy seasons. Those areas include the north-eastern highlands, which TMA defines as the Kilimanjaro, Arusha and Manyara regions. That covers the classic northern safari circuit and the mountain.

The short rains, Vuli, run from October to December. TMA's Vuli outlooks cover Arusha, Kilimanjaro and Manyara, plus Unguja and Pemba, the two main islands of Zanzibar.

The dates move from year to year. For 2026, TMA expected the long rains to end in the fourth week of May or the first week of June over most of those areas. The UK government also warns that park roads can become hazardous or impassable after heavy rain, and that a 4-wheel drive may be essential.

The two gaps between the rains, January to February and June to September, are the easiest months to plan around.

Where is the Great Migration each month?

The wildebeest move in a long loop through the Serengeti ecosystem, following rain and fresh grass. National Geographic's account (April 2026) gives this typical pattern:

January to February: calving season. Between January and April the herds gather in the southern Serengeti, and most calves are born in January and February.
April: as the dry weather sets in, the herds push off.
May to July: they move through the Western Corridor.
From early July: they head north and cross the Mara River. By August many are on the grasslands of Kenya's Masai Mara.
October: the rains return to the Serengeti ecosystem and the herds turn south.
November to December: they stop in the middle of the Serengeti before gathering in the south again in January.

None of this runs to a strict schedule. Rainfall, fire and other conditions shift where the animals go. In 2014, unusually lush rains meant much of the herd stayed in the southern Serengeti.

More on the park itself in our Serengeti guide.

1.3 million
wildebeest in the herds, at the most (National Geographic): 200,000+
zebra travelling with them: Half a million
calves that may be born in a year

When is the best time to climb Kilimanjaro?

Kilimanjaro sits in the north-eastern highlands, so the same two rainy seasons apply. The drier windows are January to February and June to September. Climbing in the rains is possible, but the trails are wetter and the views less reliable.

Whatever the month, it is cold at the top. The British Mountaineering Council notes that temperatures range from over 25°C at the base to well below freezing at the summit, so you pack for winter on summit night even in a dry month.

Weather is only half the decision. The number of days you take matters more for your chances of reaching the top; our guide to Kilimanjaro altitude and acclimatisation explains why. Routes and dates are on our Kilimanjaro page.

When is the best time to visit Zanzibar?

Zanzibar gets both rainy seasons too. TMA's outlooks name Unguja and Pemba for the Vuli rains from October to December, and its 2026 long-rains outlook forecast normal to above-normal rainfall for both islands. The same dry gaps apply: January to February and June to September.

Two practical points for the islands. Malaria is a risk on Zanzibar, so the advice in our Tanzania travel tips applies there as well. And since 1 October 2024 visitors have needed travel insurance from the Zanzibar Insurance Corporation. More on the islands in our Zanzibar guide.

Which months suit which trip?

January and February: between the rains. Calving in the southern Serengeti, a dry window on Kilimanjaro, and Zanzibar between rains.
March to May: the long rains. Expect muddy park roads, and some may be closed. The herds usually leave the south around April.
June to September: the longest dry stretch. The herds move through the Western Corridor into early July and then north towards the Mara River. A good window for Kilimanjaro and the beach.
October to December: the short rains. The herds turn south in October and spend November and December in the middle of the Serengeti.

If you're combining a safari, a climb and a beach stay, the dry gaps let you do all three without fighting the weather. Tell us your dates on plan your trip, or browse our tours and safaris.

Questions

When is the wildebeest calving season?

Typically January and February, on the plains of the southern Serengeti. The herds gather there between January and April, but timing shifts with the rain each year.

When do the herds cross the Mara River?

Usually from around early July, with many reaching Kenya's Masai Mara by August. They tend to turn south again once the rains return in October.

Can I climb Kilimanjaro in the rainy season?

Yes, but trails are wetter during the long rains (March to May) and the short rains (October to December). The summit is well below freezing in any month.

When does it rain on Zanzibar?

Zanzibar gets the long rains from about March to May and the short rains from October to December, according to Tanzania Meteorological Authority outlooks. January to February and June to September are drier.