The Songhay are the fourth-largest ethnic group in Niger, West Africa. There are also considerable Songhay populations in Mali and Benin. They are closely related culturally to the Zarma. The Songhay are spread over a large area of eastern Mali, western Niger, and northern Benin. The largest concentrations are in eastern Mali and western Niger. In eastern Mali, the Songhay population lives along the Niger River from east of Lake Debo to south of Ansongo. In Niger, Songhay live along the Niger River from Firgoun to Sansane-Hausa, as well as west of the Niger north of Niamey in the region of Tera. In regions far from the Niger, the geography consists of laterite plateaus broken by occasional mesas. The vegetation in Songhay country, which is by and large scrub desert, is sparse. Water is deep and in short supply, except in the land along the Niger River, which is lush with wild vegetation as well as vegetable and fruit gardens. The climate of Songhay country, like that of Zarma country, consists of a single rainy season that begins in June and ends in September. Average rainfall varies from 20 centimeters in the north of Songhay country to roughly 40 centimeters in the south. The average high temperature, as in Zarma country, is 36° C, but temperatures reach the mid-40s at the peak of the hot season in mid-May. The average low temperature is 22° C.