The Great Migration in Tanzania is a year-round spectacle, with peak events occurring between January and March, and July to October. In January to March, the herds gather in the southern Serengeti and Ngorongoro Conservation Area for calving season. From April to June, they journey north, crossing the Grumeti River in June. The climax is the Mara River crossing from July to October, ... https://www.gondwanaecotours.com/travel-journal/when-is-the-great-migration/