Tanzania's Northern Circuit links the Serengeti's Great Migration with Ngorongoro Crater's caldera floor, Tarangire's elephant herds, and Lake Manyara's tree-climbing lions, all within a week's safari from Arusha.
Dry season with Serengeti migration in the western corridor July-August, Mara River crossings late August-September, and game concentrations highest.
Calving season in the southern Serengeti's Ndutu plains with 8,000 wildebeest born daily, predator action at peak, and short dry season for accessible game drives.
Long rains with afternoon storms, lower rates across migration camps, and the Serengeti at its greenest with newborn herbivores still visible across the plains.
Short rains with manageable afternoon storms, wildebeest moving south toward calving grounds, and the country at peak green before the long rains return in March.