Wildlife
The Great Migration: A Month-by-Month Guide
The Great Migration is the year-round, roughly circular movement of about 1.5 million wildebeest, along with hundreds of thousands of zebras and gazelles, through Tanzania’s Serengeti ecosystem and Kenya’s Masai Mara. The herds follow rain and fresh grass, so there is no single “migration season” — there is a migration every month, just in different places.
How the migration works
The migration is driven by rainfall and grazing. Wildebeest need short, nutrient-rich grass and regular water. As rains move across the ecosystem, the herds move with them in a broad clockwise loop: south in the wet season, west and north as the plains dry out, then back south when the short rains return.
It is not a single orderly column. The herds split, merge, double back and spread across hundreds of square kilometers. Some groups cross a river several times in a week. That unpredictability is why good guides and well-located camps matter more than precise dates.
Month by month: where the herds usually are
| Months | Usual area | What is happening |
|---|---|---|
| January–March | Southern Serengeti, Ndutu area (Ngorongoro Conservation Area) | Calving season, peaking around February; intense predator activity |
| April–May | Moving north-west through the central Serengeti | Long rains; herds spread out and begin the rut |
| June–early July | Western corridor (Grumeti River) and central Serengeti | Grumeti River crossings, known for large crocodiles |
| July–October | Northern Serengeti (Kogatende, Lamai) and Kenya’s Masai Mara | Mara River crossings, the most famous spectacle |
| November–December | Moving south through the eastern Serengeti and Loliondo area | Short rains pull herds back toward the southern plains |
Calving season (January to March)
Calving season is the best time to see the migration if you want huge herds in one place and dramatic predator action. Around half a million calves are born over a few weeks, most of them in a short peak usually around February. Wildebeest calves can stand within minutes and run with the herd soon after, but lions, cheetahs, hyenas and jackals take advantage of the abundance.
The short-grass plains around Ndutu and the southern Serengeti are open and easy to view. Afternoon thunderstorms are possible, but this is a short dry spell between the rains, and it is often less crowded than the Mara in August.
The river crossings (July to October)
The Mara River crossings are the migration’s headline event: thousands of wildebeest gathering on a bank, hesitating, then plunging into the water past waiting crocodiles. Crossings happen at many points along the river in both the northern Serengeti and the Masai Mara, often repeatedly in both directions.
Be realistic about crossings:
- They cannot be scheduled. Herds can mass on a bank for hours and then walk away. Patience and several full days in the area improve your chances greatly.
- Sightings can be crowded. In the Masai Mara reserve, popular crossing points can draw many vehicles. Private conservancies bordering the reserve limit vehicle numbers, and the northern Serengeti tends to be quieter, though it is getting busier.
- Follow ranger rules. Vehicles must keep back from the banks so they do not block the animals’ route. Good guides position you without disturbing the crossing.
Serengeti or Masai Mara?
Both are part of one ecosystem, separated only by an international border. The animals don’t notice it; your itinerary will.
- Tanzania’s Serengeti is far larger, so the migration is there for most of the year. It suits longer trips and pairs naturally with Ngorongoro Crater, Tarangire and Zanzibar.
- Kenya’s Masai Mara is smaller and more compact, easily reached by short flights from Nairobi, and has an excellent resident predator population. Its surrounding conservancies allow activities that the main reserve does not, such as walking safaris and, in some, night drives.
- Crossing between the two on the ground is generally not possible as a tourist route; most travelers fly between Nairobi and Arusha or Kilimanjaro.
Planning tips
- Stay longer in fewer places. Three or four nights in the right area beats one night in each of four camps.
- Consider a mobile camp. Some seasonal camps relocate to follow the herds. See safari types compared.
- Book early. Camps near the Mara River fill well in advance for August and September.
- Look beyond the wildebeest. Even in “off” months, the Serengeti and Mara have superb resident wildlife.
- Pack for dust and cool mornings. Our safari packing list covers what you need.
Responsible viewing: Never encourage a driver to go off-road where it isn’t permitted or to crowd a crossing point. Pressure from vehicles can turn animals back, and park rules are there for good reasons.
Quick answers
When is the best time to see the Great Migration?
For river crossings, July to October in the northern Serengeti and Masai Mara. For calving and predator action, January to March in the southern Serengeti. Timing shifts with rainfall each year.
How many animals are in the Great Migration?
Roughly 1.5 million wildebeest, plus several hundred thousand zebras and gazelles. Figures vary by count and year, which is why sources quote different totals.