Over a million wildebeest, moving in a rough annual circuit. Here's where they actually are, month by month.
The Great Migration isn't a single event you can circle on a calendar — it's a continuous, roughly annual circuit of over a million wildebeest and hundreds of thousands of zebra moving through the Serengeti-Mara ecosystem in search of grazing and water. Timing genuinely matters if you're chasing a specific moment, like a river crossing. Here's the realistic month-by-month picture.
The herds gather on the short-grass plains of the southern Serengeti and Ngorongoro Conservation Area, where up to 8,000 calves can be born in a single day at the peak of calving season (late January to February). It's also peak predator action — lion, cheetah and hyena all know exactly what this means. This is one of our favorite windows: dramatic action, good weather, and fewer crowds than the famous crossing months.
As the plains dry out, the herds start moving north and west through the central Serengeti. This is Tanzania's rainy season — genuinely wetter, with some roads harder to travel, but also lush, green and quiet. Budget-conscious travelers and photographers who don't mind a shower or two often find this an excellent value window.
The migration reaches the western corridor and the Grumeti River, where crossings can happen (with resident crocodiles very much part of the drama) though generally on a smaller scale than the famous Mara crossings later in the year. This is a good transitional window — drier conditions returning, herds on the move, fewer crowds than peak season.
This is what most people picture when they imagine the Great Migration — mass river crossings at the Mara River in the northern Serengeti, with genuine chaos, crocodiles and adrenaline. It's also peak season: the driest, most reliable weather, and the busiest camps and vehicles. If a river crossing is specifically what you're after, this is the window, and it's worth booking well in advance.
The herds begin moving back south toward the plains where calving season will begin again, often triggered by the first short rains. It's a quieter month with unpredictable but generally brief rain showers — a good option if you want migration-adjacent scenery without peak-season crowds or pricing.
If a specific river crossing is the whole point of your trip, aim for August through October and book early. If you want dramatic predator action with fewer people around, consider the calving season in February. And if flexibility and value matter more than a specific migration moment, the shoulder months (April-May, November) reward travelers willing to embrace a little rain. Tell us what you most want to see and we'll build the timing around it — see our Great Migration safari itineraries for specific options.
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