December to early January is also popular and the game can still be good. Once the rains come, the game tend to disperse and are not drawn to the waterholes. The animals are still there but are more difficult to locate. April is an excellent birding time. Almost any time.
Winters are usually mild, but a light jacket is required.
Tanzania - January to March. Both Tanzania and Botswana have great game viewing. Tanzania however, tends to have a greater number of animals. We would suggest considering Tanzania for your trip since you have not been to Africa before. Tips can be paid in either Pounds Sterling or US dollars.