The Great Migration is a year-round loop, not a Mara event. Roughly 1.3 million wildebeest, 200,000 zebra, and a quarter-million gazelle move in a slow counter-clockwise arc across the Serengeti–Mara ecosystem, following the rain and the grass it produces. The Mara holds the herds for roughly four months — July through October — and a tail of the reverse into November. The other eight months are the Serengeti's.
What follows is the route in order, with notes on what the country looks like each month, where the herds are, and what to expect if you are coming for them.
The route, briefly
The herds calve in the southern Serengeti in late January and February, on the short-grass plains around Ndutu. By March the calves can travel and the grass is failing; the migration begins to drift west and north through April, May, and June. By late June and early July the first columns reach the Mara River and the Kenyan border. From July to October the herds work the Mara plains, recrossing the river repeatedly. In November the rains turn the grass green further south, and the migration begins the return.
January–February — calving in the Serengeti
The herds are not in the Mara. The wildebeest are giving birth on the southern Serengeti plains, roughly five hundred kilometres south of the Mara River. The Mara itself is quiet, green from the short rains, and at its best for resident game — strong predator activity, fewer vehicles, river levels low.
March–May — the long rains and the slow drift
The migration moves north and west across the Serengeti. The Mara stays quiet. Long rains soften the plains; many lodges in the Reserve operate on reduced occupancy. April is the most beautiful, least-photographed month of the Mara year — and the least likely month to see the migration.
June — the country dries
The grass yellows. The first columns of wildebeest reach the southern boundary of the Mara ecosystem on the Tanzanian side. Crossings of the Sand River — the easier southern crossing — can begin in late June, though they rarely draw crowds.
July — the first arrivals
The first major herds enter the Mara plains on the Kenyan side of the river. River crossings of the Mara River begin, typically in the second half of the month. Vehicle density rises. Predators move with the herds, and lion sightings in particular intensify — the prides on the river belt are working harder than at any other time of year.
August — peak crossings, peak crowds
The most photographed month of the Mara year. Crossings of the Mara River are most frequent now, often multiple per day across several known crossing points. Vehicle pressure at the river is at its highest; at popular points, twenty or thirty vehicles can be queued before a crossing begins. The light is good through long working windows; the air carries dust by mid-morning.
If a river crossing is the reason you are coming, this is the highest-probability month — but not the only one. The crossings continue into September and early October, with less crowd pressure.
September — the second peak
Almost as productive as August, with thinning crowds. Crossings continue. The herds are working the central and northern Mara plains. Predator activity is at the year's high. Light is the cleanest of the season — the dust has not yet softened the dawn the way late October will, and the late-afternoon hours are reliably golden.
For most photographers — and for most travellers who want to see the migration without the August queue — September is the strongest single month.
October — the last crossings
The final wave. Crossings still occur, less frequently. Crowd pressure drops noticeably from the second week onward. By late October the southward drift has begun and herds are leaving the northern Mara. Resident predators stay; the wildebeest do not.
November — the reverse
The short rains begin. Sky turns dramatic; the plains turn green within a fortnight. The wildebeest move south, often re-crossing the Mara River in the opposite direction at the same crossing points they used in August. The reverse crossings draw far fewer vehicles, are less predictable, and produce some of the most painterly light of the year. The least-marketed month of the migration.
December — short rains, resident game
The migration has, in most years, returned to the Serengeti. The Mara is green, quiet, and predator-rich. Lodges are mostly open. This is the off-season pricing window for migration-priced months that flank it on either side.
What a "river crossing" actually looks like
A river crossing is, in the lived sense, a long stretch of nothing followed by a short stretch of everything. Herds gather at a crossing point and stand. They graze. They drift away. They come back. Two hours pass. Four hours pass. Then one animal — often a zebra, occasionally an unusually committed wildebeest — steps into the water, and within twenty seconds five hundred animals are following. The crossing itself takes between three and twenty minutes. Then it is over.
The photograph in your head is the climax. The morning is the wait. Bring water. Bring patience. Bring an empty bladder.
Practical notes
- River crossings are not guaranteed in any particular week. A good guide reading the herds will significantly improve your odds.
- Vehicle pressure at the river is real. The Mara Triangle (the western section of the Reserve) historically holds fewer vehicles than the eastern section, by Reserve management.
- Most lodges raise rates by 30–50% for August–September. October rates are 10–20% lower; November is often half of peak.
- A four-night minimum is the practical floor for migration-focused trips. Two crossings per stay is a fair statistical expectation in August–September.
The shorter version
If you are coming for the migration, come in September. If August is your only window, go and accept the crowds. If you are open to a quieter trip with a smaller chance of a crossing, late October or November is the most under-rated migration window of the year.
