About two-thirds of Nigeria lies in the watershed of the Niger River, which empties in to the Atlantic at the Niger Delta, and its major tributaries: the Benue in the northeast, the Kaduna in the west, the Sokoto in the northwest, and the Anambra in the southeast.
As in most of West Africa, Nigeria's climate is characterized by strong latitudinal zones, becoming progressively drier as one moves north from the coast. Rainfall is the key climatic variable, and there is a marked alternation of wet and dry seasons in most areas.
Nigeria is divided into thirty-six states and one Federal Capital Territory, which are further sub-divided into 774 Local Government Areas (LGAs). The plethora of states, of which there were only three at independence, reflect the country's tumultuous history and the difficulties of managing such a heterogeneous national entity at all levels of government.