East Africa is widely regarded as a fantastic year-round safari destination. Its temperate climate, seasonal migration, and abundant resident wildlife mean there is no single best time for a safari in East Africa. The most important thing to keep in mind when planning your East African safari is how the rainy and dry seasons influence the game viewing experience and how the rains drive the Great Wildebeest Migration.
In East Africa (Uganda, Rwanda, Kenya and Tanzania) the dry season is from late June to September. The region typically experiences two wet seasons. The main wet season lasts from April to early June, and there is a more sporadic wet season from October to December.
Generally speaking, the dry season is best for game-viewing, while the wet season is often better for birding and baby animals.