Travel deep dive
The Great Migration: Where the Herds Are, Month by Month
The commonest misunderstanding about the Great Migration is that it is an event with a date. It is not. Something over two million wildebeest, zebra and gazelle move continuously around a single ecosystem, following rain and the grass that follows it, and they are somewhere every day of the year. That changes the planning question completely. You are not asking whether you have come at the right time — you are asking where the herds will be in the month you can travel, and then putting yourself in that part of the ecosystem rather than in the part the brochure photographed.
Updated 2026-08-15
The engine: rain, grass and minerals
The migration runs on grass, and grass runs on rain. The southern Serengeti's short-grass plains sit on volcanic soil that produces grazing unusually rich in calcium and phosphorus — exactly what a lactating female needs — but they are open, exposed and dry out fast once the rains stop. The northern and western woodlands hold water and cover for longer but offer poorer grazing. So the herds spend the wet months in the south where the food is best, and are pushed north as it dries, arriving at the permanent rivers when nothing else is left.
That is the whole mechanism, and it explains everything else: why the animals give birth in one place at one time, why they concentrate so densely in the south, why they string out into columns as they move, and why they end up crossing rivers in the middle of the year rather than at either end. The cycle is anticlockwise, roughly, and it takes a year.
It is also why the calendar is approximate and always will be. The herds follow the rain, and the rain varies. An early or late wet season moves everything by weeks, which is why any month-by-month account, including this one, should be read as the pattern rather than the schedule. Camps and guides track the herds daily; a good operator will tell you where they actually are before you commit.
Calving, roughly January to March
In the southern Serengeti and the Ndutu area the herds gather on the short-grass plains and give birth — hundreds of thousands of calves within a few weeks, at a rate that peaks in the thousands per day. It is a synchronised strategy: so many young arrive at once that predators cannot take them all, and the survivors are on their feet within minutes.
For a visitor this is the densest wildlife experience the ecosystem offers. The animals are concentrated rather than strung out, the plains are open so sightlines run for kilometres, and the predator activity is sustained rather than occasional — lion, cheetah and hyena work the herds continuously, and cheetah in particular hunt well on open short grass. The landscape is green, the light after rain is superb, and there are markedly fewer vehicles than in the crossing months.
The trade-off is that it rains, in short heavy bursts rather than all day, and that the south is a different part of the park from where most first-time itineraries go. If your dates are flexible and your priority is wildlife rather than a specific photograph, this is the season to take.
The crossings, roughly June to October
As the plains dry the herds move west and then north, and by the middle of the year they meet water: first the Grumeti in the western corridor, then the Mara river in the far north. The crossings are what the migration is famous for — thousands of animals massing on a bank, hesitating, and then committing all at once into fast water where crocodiles are waiting.
What is worth knowing before booking a trip around them is how they actually work. A crossing is not scheduled and cannot be predicted more than an hour or two ahead; herds mass at a bank and may wait a day, cross, or turn away entirely. Seeing one involves being in the right place with time to spare, and vehicles concentrate at known crossing points in numbers that are themselves part of the experience. Some visitors wait three days and see nothing; some see two in a morning.
Plan for it as a possibility rather than a purchase. Give the northern Serengeti several nights rather than one, understand that the animals are also crossing back and forth rather than moving one way, and treat the surrounding game viewing — which is excellent in its own right — as the trip rather than as the wait.
Where to stay, and how to intercept
Two kinds of accommodation answer this problem differently. Permanent lodges and camps sit in a fixed place, which is fine if that place is where the herds are during your month. Mobile camps move several times a year specifically to stay with the migration, packing up and re-erecting in the next area — they are simpler in comfort and considerably better positioned, and for a migration-focused trip they are usually the right answer.
The practical booking rule is that migration-season camps in the herds' current path fill a year or more ahead for the peak weeks, which is unusually far out even by safari standards — and how you reach them, including the luggage limit that governs what you can bring, is in the Tanzania transport guide. If your dates are fixed and your priority is the migration, book early and choose the region by month rather than choosing a camp you like and hoping.
And a note on expectation, because it decides whether the trip satisfies. The Serengeti is a superb wildlife destination in any month with or without the herds, holding resident lion, leopard, elephant and cheetah year-round across a landscape that is worth the journey by itself. Visitors who arrive wanting the ecosystem have a great trip whatever the animals are doing. Visitors who arrive wanting one photograph are at the mercy of an animal that has never seen a calendar.