The Serengeti plays host to the annual migration. With an elevation of between 900 and 1800m, an annual temperature range of between 21°C and 27°C and a precipitation range of 950 to 1150mm, the area’s climate - in normal years - is temperate and experiences a bimodal rainfall pattern, with the short rains occurring in November and December, the long rains in March - May. The Serengeti is not blessed with large numbers of permanent water sources: the migration follows the rain, its quest good grass and high quality water.
As the rains move south - between October and January - the migration can be found first above the western Loliondo and Lobo Hills area (October), then a halfway down the eastern corridor, in the Nyabogati and Ngare Nanyuki rivers areas (November and December), before arriving in the south east, in the Ngorongoro Conservation Area (January and February), where it spends the short dry season. From here it gradually moves west and - between April and June - north, following the long rains, and can be found on the Grumeti waterfront (June / July) and massing along the Mara River (July / August), before crossing the border into Kenya.
The south and south east is the most popular area of the park, its short grass plains habitat the epitome of what everyone imagines the Serengeti to be. The plains are broken only by small rocky hills (koppies) and the occasional strip of riverine habitat. Everywhere else is grass. The combination of short grasses and poor tree cover makes for excellent viewing, even during the rains. In the north of the park - characterised as it is by acacia woodland, riverine habitats and intermittent tracts of grasslands - the wildlife disperses during the rainy season and is consequently that much harder to spot. The same is true of the western corridor, though the migration’s main river crossings generally take place during the long dry season.