Dry season or green season? A month-by-month guide to weather, wildlife, crowds and what a Tanzania safari actually costs in each window.
If you want one line: June to October for wildlife, January to March for the calving season and fewer vehicles, and December to February for Zanzibar's clearest water.
Tanzania sits just south of the equator, so there is no winter in the European sense. What changes is rainfall, grass height and where the herds are - which changes what you actually see.
The long dry season is peak safari. Days are 25 to 30 C on the plains, nights drop to 12 to 15 C, and the bush thins out, which makes animals easier to find. This is also when the wildebeest move into the northern Serengeti and cross the Mara River, usually from late July into early October.
It is the most expensive window and the busiest, especially in the Serengeti. If you travel in August, book lodges six to nine months ahead - our Grand Northern Safari is built around this exact season.
A brief rainy spell in November, then a dry, green, relatively cheap December. The herds are moving back south, the parks are quiet, and storms in the afternoon clear the dust from the air. Photographers often prefer this window for the light.
Zanzibar is hot and humid but drying out nicely by mid-December.
The short-grass plains of Ndutu and the southern Serengeti fill with wildebeest and zebra dropping their calves - up to 8,000 a day at the peak - and the predators that follow them. Six cat species are possible in Ndutu, including caracal and serval.
It is a much better-value window than July and August, and the game viewing is arguably more dramatic. See the seven-day calving safari we run for this season.
The wettest months. Some camps close, roads in the parks get heavy, and the crater can be misty for hours. On the other hand, hotel rates drop by 30 to 45 percent, everything is emerald green, and you will have sightings almost to yourself.
If your priority is photography of lush landscapes or a cheap first safari and you can be flexible about a washout afternoon, April is genuinely underrated.
The island has its own rhythm: dry and breezy June to October, hot and clear December to February, rainy April to May. Seaweed farming, dive conditions and the kitesurfing wind all follow this cycle too.
Our Zanzibar Island Escape runs year-round; we simply adjust the hotel tier to the season.
The clearest and driest climbing windows are January to mid-March and June to October. March to May and November are wet: you can still climb, but expect snow, sleet and slower days on the Barranco Wall.
Route choice matters more than month. Compare the Machame and Marangu routes in our Kilimanjaro guide.
July, August and the Christmas week are the three most expensive and most crowded periods. Late June, September and early March are the sweet spots: dry, clear, quieter, and 15 to 25 percent cheaper than high season.
If your dates are fixed, tell us and we will plan around them rather than pushing you towards our preferred season. The packages page shows what each tier costs.
Send your dates and we will build a route around the season you are travelling in, with the price in the first reply.
Two full days in Ndutu for the calving season and the cats that follow it, a crater descent, and a night in the middle of the central Serengeti.
The complete northern circuit including the Kogatende sector, where the wildebeest cross the Mara River between July and October.
Five nights on the island: Stone Town's alleys, a spice farm, dolphins at Kizimkazi and long, unhurried beach days at Amaan Beach Bungalows.
Free 30-minute call with a Tanzania expert, no sales script.