Great Migration & Kilimanjaro — The Complete Timing Guide

Wildebeest herds gather in the short-grass plains of the southern Serengeti and Ndutu region. Calving season starts in earnest — up to 8,000 calves born per day at peak. The grass is short and nutrient-rich. This is some of the best predator-viewing in Africa: lion, cheetah, hyena, and jackal all hunting around the vulnerable newborn herds. Dry and clear — same weather window as Kilimanjaro's best season.

The most intense calving period. Huge concentrations of wildebeest on the southern plains. Predator action is exceptional — cheetah litters emerging, lion prides working coordinated hunts. The best month for predator-focused safaris. The plains are a sea of wildebeest and zebra.

The last of the calving. Herds begin to stir and move north as the short rains end. The transition month. Weather on Kilimanjaro starts becoming variable — the long rains approach. The migration is in its least dramatic phase.

The long rains fall across the Serengeti. Herds move northwest through the western corridor — a lush, green landscape. Less dramatic than calving or river crossings, but the western corridor is beautiful and very uncrowded. Not recommended for Kilimanjaro (long rains are at their peak on the mountain), but if you are already in Tanzania for other reasons, the western corridor in April has its own quiet appeal.

Herds continue their movement north through the western corridor. The grass is tall and green. The rivers are swollen from the long rains — the Grumeti and Mara rivers are crossing points. Late May is when the herds begin to bunch up at these river crossings in preparation for the big push north. Some of the earliest crossings can happen in late May.

The dry season begins on Kilimanjaro. The migration arrives in the northern Serengeti in force. The herds mass at the Mara River — hundreds of thousands of animals concentration at the riverbanks. The first Mara River crossings can happen as early as late June. Kilimanjaro conditions are excellent from mid-June onward. This is one of the best combined windows of the year.

The river crossings begin in earnest. The first major crossings of the season — often in early to mid-July. Wildebeest surge across in massive groups, crocodiles in the water, lions on the banks. The spectacle is extraordinary. Kilimanjaro is at peak season (July is one of the two best months on the mountain — 95%+ success rates, clear skies, cold but reliable). This is the classic combined window.

The most dramatic phase of the migration. River crossings happen daily, sometimes multiple times per day. The herds are enormous. The action is constant. August is peak crowding on both Kilimanjaro and in the northern Serengeti — you are sharing the experience with many others. The best weather on the mountain. The best wildlife viewing on the migration.

Crossings continue daily. September often offers the most dramatic single crossing days of the season. Herds start to thin as some begin crossing into the Maasai Mara in Kenya. Kilimanjaro is still excellent — slightly less crowded than August as European school holidays end. One of the best months for both the mountain and the migration.

The crossings begin to slow as the herds that crossed into Kenya start moving south through the eastern parts of the ecosystem. Some return to Tanzania. The northern Serengeti remains excellent for viewing residual herds and late crossings. Kilimanjaro conditions are still very good — October is the last month of the dry season with 93–95% summit success rates. Shoulder-season crowds.

The short rains begin and the herds move south and east, following the green flush. The migration is in transition — less concentrated but spread across a wider area. Not ideal for Kilimanjaro (short rains begin) but still possible. The Serengeti is quieter and green.

The herds spread across the southern Serengeti plains as the short rains bring fresh grass. Beautiful green landscape. Pre-Christens crowding as families arrive for holiday travel. Weather becomes variable on Kilimanjaro. Summit success rates drop to 85–90% due to cold and some precipitation. The migration is dispersed rather than concentrated.