Kenya and Tanzania are best known for the migration of 1.3 million wildebeest and hundreds of thousands of zebra that pass through the Maasai Mara and the Serengeti each year. The best time to catch the massive herds on the move is June in the Serengeti or August-September in the Maasai Mara. The migration is weather dependent, so there are years when the herds never reach the Maasai Mara and others when they cross into Kenya in early June. Although the migration is fascinating, consider it an extra rather than a focal point of your trip. Zebra and wildebeest usually give birth in the Southern Serengeti between late January and the end of February.
If your focus is primates or birds, Uganda and/or Rwanda are ideal. Trekking for mountain gorillas is available in both countries. Rwanda is host to a dozen other species of primates, including wild chimpanzees and in Uganda over 550 species of birds have been recorded. Uganda can be visited any time of year; the warmest months of the year are December through February. Rwanda can also be visited at any time of year. The dry season from mid-May to mid-October is easier for tracking mountain gorillas. Peak season for tracking is July and August.
Botswana is best known for the Okavango Delta. Its annual floods are caused by storms in nearby Angola. From May-September, the water levels in the delta are at their highest, which allows for excellent viewing opportunities because much of the wildlife is concentrated on islands. In the dryer habitats of Chobe and Linyanti to the north of the delta, animals congregate around limited water supplies. December to March is referred to as the green season because at this time of year, the camps offer splendid bird watching opportunities and lush green landscapes bursting with color. Plains game begin to calve in November and game viewing can be quite rewarding with a high number of young impala and zebra, which attract the big predators.
The seasons for Zambia are very similar to Botswana, but many of the remote lodges and camps close during the rainy season and are only accessible from May to October. The Victoria Falls are at their peak in March and April with a wall of water cascading over the rock precipice. The water then slowly begins to recede with October and early November being the driest times. If you are interested in white water rafting on the Zambezi, the best time is late June to December. Rafting is prohibited from January to May due to the high waters.
South Africa has something to offer for every month of the year whether it be pristine beaches and turtle nesting or wildlife viewing.
In Namibia, the best game viewing is generally between May and October, with dry, warm, sunny days and freezing temperatures at night and early morning. The hottest months are from December through February. Game drives are scheduled at dawn and dusk as animals and travellers seek out the shade during the heat of the day. The bird watching season is best from November to March.