The Answer to this question is very subjective and depends on your exact destination and purpose in East Africa. However, the seasons here are broadly divided into two categories : the rainy and dry seasons.
There is no single best time to visit East Africa but there depending on whether you are going to Masai Mara or the Serengeti, or the other National Parks, if you are going to specifically see the Great Migration ( either in Kenya or Tanzania ), or if you are combining your visit along with one of the other attractions of the place, like climbing Mount Kilimanjaro, you will have to take into account the relative merits of each. Each season here has its advantages and disadvantages and each destination has its best moments.
The wide plains are home to many animals.
Geographically, the Serengeti and Masai Mara are part of the same ecosystem of grasslands, of which Tanzania’s larger share is called the Serengeti and Kenya’s share is called the Masai Mara. The Great Wildebeest Migration takes place in these regions, specifically starting from the Serengeti during the dry season to the Masai Mara, and then back. However, there are differences between the two, which stems from the geography, which affects the rainfall received by the two regions, and thus affects the vegetation. This in turn affects the wildlife and is ultimately responsible for the unimaginably vast movement of the Wildebeest.
The Serengeti is much bigger, and the wildlife concentrations are not as high or as evenly distributed here, as is the case with most of the Masai Mara.The conditions in the Serengeti are also much more season dependent, and the areas can change dramatically through the year, from season to season. The contrast between the rainy and the dry season is especially stark, with the southern region of the Serengeti losing much of its appeal to the animals because of the lack of grazing and fresh water during the dry season (especially from July to October). This therefore becomes becomes a much harsher environment for the wildlife and thus leads them to greener pastures in the Masai Mara.
The Masai Mara, on the other hand is a smaller National Park than the Serengeti, but because of the more regular rainfall it receives, is a vast grassland, and therefore has an abundance of wildlife. Thought the Masai Mara also changes through the year, it isn’t as dramatic as the Serengeti. Because of the varied conditions in the Serengeti, there is a distinct ‘migration season’ in the Masai Mara, which usually lasts from July to October. There is a also a lot more resident wildlife which does not migrate in this region.
Wildebeest crossing the Mara River during the Great Migration.
The Great Migration is caused by the rainfall patterns in the region. The Serengeti, lying in Tanzania experiences much higher rainfall than Kenya from March to May, and then again in November and December. Thus the environment is particularly suited for the wildlife here. But during the months of June to October, the rainfall drops sharply, leading to very poor conditions, both for feed and water, thus prompting the herds to migrate to the relatively luscious fields of the Masai Mara in Kenya. A quick look at the following graph will show the stark difference.
The rainfall received is starkly different. See April and July.
If you are especially interested in viewing the Great Migration, you will have to be diligent about your timing. The Serengeti, being larger, offered a better time frame for this. You can visit the different regions of the Serengeti. Particularly helpful are the following time ranges:
The Masai Mara, on the other hand, gives you a chance to view the Great Migration from late July until the end of October.
Apart from the Great Migration, there are other National Parks and areas that you can visit in East Africa to experience An African Safari and see wild game in their natural environment.
The park regulations affect your safari experience as well as the permissible activities. For most of the Serengeti National Park, you are limited to game drives by day. In fact, you will mostly be sticking to the well traversed roads and paths. Also note that there are very few areas in the Serengeti ecosystem where night drives are allowed. Even walking here is extremely restricted and well monitored. This is also true of the official Masai Mara Game Reserve. However, the Mara private conservancies permit the unparalleled experiences of off road driving, walking and even night drives. Do note that these are not offered at all camps in Kenya, but can significantly enhance your Safari experience. If you are planning to make your own travel arrangements, this article for Kenya will help.
The weather patterns are responsible for the game density and your location combined with the time of the year, are crucial factors in making your decision. Here, given below are the weather patterns grouped by months, for both Kenya and Tanzania. These will not only provide a good overview, but may also help you plan your trips, if you are unable to travel during a particular time for some reasons ( medical, psychological or otherwise )
It may rain anytime in the Masai Mara.
Two factors influence Kenya’s climate; the altitude, and the Indian Ocean’s monsoon winds. These lead to the following weather conditions:
Tanzania’s climate is more varied and the months are usually experienced as follows :
Whatever time you decide to go, do ensure that you are adequately prepared. Do read up about what to expect, that you have packed for your Safari adequately, have had your immunization shots and have booked a trip with a good agency. Have fun!