When's the best time to visit Tanzania?

In Tanzania, when it rains, it pours. Storms typically last for about an hour, usually in the late afternoon. Essentially, during the rainy season it is cooler, cheaper and less crowded in the parks. The below info is also covered in our When To Go To Tanzania article.

Northern Circuit (Arusha, Lake Manyara, Mkomazi, Ngorongoro, Serengeti, Tarengire)

• Jan/Feb/Mar — Periodic rains. Elevated costs. Busy; many lodges fully booked.
• Apr/May — Rainy season. Lower costs. Slow, few travelers.
• June — Rain ends. Average costs. Busy.
• July/Aug — Dry season. Elevated costs. Busy; many lodges fully booked.
• Sept — Dry season. Average costs. Slower, but still busy.
• Nov — Short rains. Average costs. Slower, but still busy.
• Dec — Rain ends. Peak holiday costs. Peak holiday season.

South (Mikumi, Ruaha, Selous, Undzungwa)

• Jan-Apr — Rainy season. Reduced costs. Slow; many camps closed.
• May — Rain ends. Average costs. Busy.
• June-Dec —  Dry season. Elevated costs. Busy; many lodges fully booked.

West (Gombe, Katavi, Mahale)

• Jan/Feb — Short dry season. Reduced costs. Second best time to visit.
• Mar/Apr — Long rainy season. Costs reduced. Some camps closed.
• May-Oct —  Dry season. Elevated costs. Peak season; best time to visit.
• Nov — Short rains. Costs reduced. Fewer travelers.
• Dec — Rain ends. Costs reduced. Fewer travelers.

Zanzibar

• Jan/Feb/Mar — Tropical, hot, and humid. High season. Busy; many lodges fully booked.
• Apr/May — Rainy season. Lower costs. Slow, few travelers.
• June/July — Tropical, hot, and humid. High season. Busy; many lodges fully booked.
• Aug/Sept — Tropical, hot, and humid. Peak season. Very busy; many lodges fully booked.
• Oct/Nov — Short rains. Average costs. Slower, but still busy.
• Dec — Rain ends. Peak holiday costs. Peak holiday season.