Month by month
Mahale Mountains in December
December is the wettest month on the entire record, the one where every figure on this page points the same direction, and where a festive supplement can turn up on your bill without warning.
If you only want the answer
December is the deep end of the green season: the most rain, the longest treks, and cooler days than any other month. Come for solitude and birding rather than an easy walk, and ask camps directly about festive pricing before you book.
December weather: the wettest month on the books
December averages 422 mm of rain across 29 days, the highest of any month in the thirty-year record, and the coolest days too, at 22.6°C. The M group is deep into its wet-season pattern by now, ranging high after months of abundant fruit, and treks reflect it: long, steep and genuinely demanding.
This is not a month for a first Mahale trip built around a short, certain walk to the chimps. It suits visitors who have already had that easier version and want to see the community, and the forest, under completely different conditions.
Festive pricing and a rougher lake
Some camps add a festive supplement through December, on top of their published rates, so confirm the actual total before you commit rather than working from a standard rate sheet. Flights remain on request only through the month, continuing the pattern set in November.
The lake is at its most unsettled all year. Boat transfers still run, but plan for delays around afternoon storms, and treat any crossing scheduled for late in the day as the one most likely to move.
What does not change even now
One cost holds steady whatever the month or however busy the calendar looks: the conservation fee stays at $80 per person per day plus 18 percent VAT year-round, with no festive uplift on the government side. Any supplement you are quoted for December is entirely the camp's own addition, not a park fee.
The multi-day route up Mount Nkungwe is not realistic in December, given how saturated the upper trail becomes after a month averaging 422 mm of rain. Stick to the standard ranger-led walks near the shore, at $20 or $25, if you want forest time beyond the chimpanzee trek itself.
Ask about the festive supplement
Ask your camp directly whether a festive supplement applies to your exact dates before booking, since the surcharge window does not always match the calendar month, and a few days either side can carry a different rate.