Oshogbo lies in the forest belt of southwestern Nigeria and has a tropical wet and dry climate. The dry season runs roughly from November to March, when the Harmattan wind blows in from the Sahara, coating everything in fine dust but keeping temperatures manageable. The wet season (April to October) brings heavy rainfall and sometimes floods the lower-lying parts of the city.
The best reason to time your visit is the Osun-Osogbo Festival, held each August over two weeks. The festival begins with the lighting of the 500-year-old Ina Olojumerindinlogun (sixteen-point lamp) and builds to the arugba procession to the river. This is one of the major cultural festivals of Yorubaland and draws tens of thousands of worshippers and visitors from across Nigeria and the diaspora. Accommodation fills up well in advance; book early.