KENYA - The best wildlife viewing months in Kenya are during the Dry season from late June to October. The wildebeest migration usually reaches the Masai Mara in July and remains until October when they move back to the Serengeti in Tanzania. Wildlife viewing is good year-round, but this can differ for some parks.
TANZANIA- From mid December to March, the short grass plains of the southern Serengeti around Ndutu and the Ngorongoro conservation are alive with migrant herds of wildebeest, zebra and gazelles. During the calving seasons of late January to mid March over 80% of the wildebeest give birth given the abundant water available.