Climate varies greatly within Tanzania. In the highlands, temperatures range between 10 and 20 °C (50 and 68 °F) during cold and hot seasons respectively. The rest of the country has temperatures rarely falling lower than 20 °C (68 °F). The hottest period extends between November and February (25–31 °C or 77.0–87.8 °F) while the coldest period occurs between May and August (15–20 °C or 59–68 °F). Annual temperature is 20 °C (68.0 °F). The climate is cool in high mountainous regions.

Tanzania has two major rainfall regimes: one is uni-modal (October–April) and the other is bi-modal (October–December and March–May). The former is experienced in southern, central, and western parts of the country, and the latter is found in the north from Lake Victoria extending east to the coast. The bi-modal regime is caused by the seasonal migration of the Inter tropical Convergence Zone.