January
Shoulder
Open but wettish. Some camps price January as peak; trekking is harder as the chimps range higher. Fair.
- January 23.7° day, 17.9° night 248 mm over 26 wet days
Month by month
Best time to visit Mahale Mountains National Park
One mechanic decides everything here: in the dry season the chimpanzees come down to the lower forest and treks are short; in the rains they follow fruiting trees high up the mountain and treks turn long, steep and muddy. From March to May the camps simply close.
If you only want the answer
June to September. July here is genuinely rainless, 0 mm on the thirty-year average, against 422 mm in December. Nothing concentrates animals like water that has stopped falling.
- January: Shoulder, 248 millimetres
- February: Shoulder, 221 millimetres
- March: Green season, 383 millimetres
- April: Green season, 293 millimetres
- May: Shoulder, 36 millimetres
- June: Prime, 1 millimetres
- July: Prime, 0 millimetres
- August: Prime, 6 millimetres
- September: Prime, 10 millimetres
- October: Shoulder, 110 millimetres
- November: Green season, 376 millimetres
- December: Green season, 422 millimetres
Prime
Dry but hot
Shoulder
Green season
Bar height is average rainfall, the figure above it is the daytime high.
The year, season by season
The periods below are how this park actually divides its year, with thirty-year climate averages against each month. Averages hide bad years: a dry January still happens, and so does a wet July.
February
Shoulder
Green season value: Greystoke drops to its lowest rates. Camps close at the end of the month. Good value, harder trekking.
- February 24.2° day, 18.1° night 221 mm over 23 wet days
March to May
Green season Shoulder
Heavy rain, all camps closed, scheduled flights paused. Do not plan a trip; the park is effectively shut to tourism.
- March 23.8° day, 18.2° night 383 mm over 29 wet days
- April 24.2° day, 18.1° night 293 mm over 23 wet days
- May 25.6° day, 18.0° night 36 mm over 6 wet days
June
Prime
Camps reopen on 1 June and flights resume. Forest still lush, chimps descending, shoulder rates. The value pick of the year.
- June 25.0° day, 16.5° night 1 mm, and rarely a whole wet day
July
Prime
Dry season proper. Chimps low, trails firm, peak trekking conditions begin.
- July 26.5° day, 16.7° night No rain on the average
August
Prime
Peak: chimps at their lowest, treks at their shortest, and the busiest month, which at Mahale still means a handful of visitors a day.
- August 27.2° day, 17.6° night 6 mm over 1 wet day
September
Prime
Peak dry and hot, with superb lake visibility for snorkelling.
- September 28.1° day, 18.7° night 10 mm over 2 wet days
October
Shoulder
Peak dry, second-busiest, the hottest month. Trekking still excellent.
- October 26.4° day, 18.6° night 110 mm over 14 wet days
November
Green season
Short rains begin, migratory birds arrive, chimps start moving uphill. Good, with flights on request only.
- November 23.4° day, 18.2° night 376 mm over 26 wet days
December
Green season
Green, festive supplements at some camps, chimps higher. Fair.
- December 22.6° day, 17.9° night 422 mm over 29 wet days
Climate figures are Open-Meteo climate normals, 1991 to 2020, measured at -6.15, 29.9. Prime, shoulder and green are worked out against this park's own year, not a fixed threshold: the four months with the least rain, the four with the most, and the rest in between. Full charts on the weather page.
Why the season matters more here than on a normal safari
On a game drive, a wet month means fewer sightings. At Mahale, a wet month means the chimpanzees are following fruiting trees high up the mountainside, and reaching them can mean four hours or more of steep, muddy climbing each way. In the dry months of July to October the community feeds low, close to the lakeshore, and treks are often measured in tens of minutes rather than hours.
The official visitor statistics confirm the shape: August is the busiest month (147 international visitors in 2024, which tells you how uncrowded even peak season is), October the second busiest, and April 2024 recorded exactly one international visitor. This is a park with a real season and a real off switch.
Practical notes
- All camps close March through May, without exception. Greystoke and Mbali Mbali Mahale both list the period explicitly as closed.
- Safari Air Link's western circuit operates 1 June to 31 October and flies on request only from 1 November to 28 February, so shoulder-season access is fragile even when camps are open.
- Book two or three trekking days whatever the month. Success rates are very high in the dry season, but this is a wild community ranging over a mountain, and no camp can guarantee chimpanzees on a single morning.
- Western Tanzania is a malaria area year-round. Take prophylaxis and bring repellent.
- Pack for both worlds: sweat-through trekking clothes with proper grip for the forest, and swimwear for the lake in the afternoon.