When to see the great migration, month by month

The migration is not an event, it is a continuous loop of roughly 1.5 million wildebeest and several hundred thousand zebra following the rain. There is no single week when it happens.

December to March the herds are on the short-grass plains in the south, around Ndutu. This is calving season — around 8,000 calves a day at the peak in February, and the highest predator activity of the year.

April and May are the long rains. Fewer visitors, lower prices, and the herds start moving northwest. Some camps close.

June and July the herds push through the western corridor and hit the Grumeti River. By late July the front runners are approaching the Mara River in the north.

August to October is river crossing season in the northern Serengeti. This is the most photographed and most expensive window.

November the short rains pull them back south and the loop starts again.

One caveat worth stating plainly: these are averages across decades. In any given year the rain can shift everything by three or four weeks.