The park lies within the Sudano-Sahelian bioregion and its associated climate. The annual rainfall in the park is 700-900 mm, largely falling between June and November, with the single dry season running from November to May. The undulating plateau marks the end of the Atakora, or Togo, Mountain range. Two large river systems, the Mékrou and Alibori, drain into the park from the Niger River and are lined by gallery forests in the south.
Fauna
The W Benin National Park and the greater Complex are deeply important for the conservation of large African fauna in the region. More than 50 species of large mammals are represented in the park including significant populations of elephant, buffalo, a dozen species of antelope, hippopotamus, lion, cheetah, spotted hyaena, striped hyaena, leopard, as well as several species of monkeys and small carnivores. Over 360 species of birds have been recorded in the park as well as 94 species of insects, 115 species of fish, and 150 species of reptiles. The park still support species that have been extirpated or threatened throughout much of the rest of Africa, including the endangered korrigum (Damaliscus korrigum), manatees (Trichechus senegalensis) that travel up the river, and the critically endangered Northwest African cheetah (Acinonyx jubatus ssp. hecki). The cheetah, lion, and korrigum make up the last remaining viable populations in West Africa.
Flora
The park is characterised by wooded savannah in the south and open savannah with thorny scrub in the north. Over 450 plant species have been identified in the park, including two endemic orchids. The iconic baobab tree is common in the area.
