Month by month
Udzungwa in December
December marks the real start of Udzungwa's wet season and the opening month of TANAPA's birding peak together, with rain climbing to 269 mm over 17 days after November's uneven start.
If you only want the answer
December is where the short rains commit fully to being the wet season, with the warmest nights of the year and the first of three months that give you the best birding at Udzungwa.
The wet season commits
Rain more than triples from November's 79 mm to December's 269 mm, and rain days climb from 6 to 17, a genuine shift from the patchy short-rains pattern into something closer to January's full wet season. Days stay warm at 28.3°C, and nights hold at 20.1°C, the highest average night low anywhere on Udzungwa's twelve-month record, warmer even than the deep wet season that follows it.
That warmth at night is the one thing that sets December apart from January and February on the ground: the trail-camp discomfort here is humidity rather than cold, the opposite problem to the one you would pack for in July.
The birding peak opens
TANAPA names December through February as its birding peak, the months when migratory species are nesting, and December is the first of the three. If the Udzungwa forest partridge or the rufous-winged sunbird, the park's two strict endemics, are what brought you here, December gives you the same access as the wetter months ahead of it, with slightly less rain to walk through than January delivers.
Sanje's three tiers pick up real volume as the rain resumes in earnest, carrying the momentum from November's short rains into a fuller flow than the dry season ever shows. The upper viewpoint over the Kilombero floodplain generally stays open in December, though as in every wet month, confirm it with your guide rather than assuming.
What to plan for
Leech activity is climbing back toward its January peak, so gaiters are worth having from this point through March. Guide assignment is still same-day at Mang'ula regardless of the month, and the only bookings worth making ahead are special or seasonal campsites and any multi-day trek, exactly as the rest of the year.
If your trip spans the year-end period, build in the same slack you would for any wet month, since a storm can add real time to a plan built on a dry-season pace.