Tanzania in December

June through September brings the Great Migration to northern Serengeti. River crossings happen July-August when millions of wildebeest brave crocodile-infested waters. December through February offers calving season in southern Serengeti — predator action peaks as big cats hunt vulnerable newborns. March through May means heavy rains and muddy roads. Some camps close entirely. But green season brings lower prices and fewer crowds if you can handle afternoon downpours. Kilimanjaro climbing works year-round except April-May rainy season. January-February and September-October offer the clearest summit views. Zanzibar stays hot and humid always. June-September brings cooler trade winds and less rain. December-March gets sticky but offers perfect beach weather if you don't mind sweating.