A narrow, low-lying plain borders Kenya's 280-mile (450-km) coast. Offshore there are coral reefs and several small islands. The rest of the eastern part of the country and almost all of the north---some three-fifths of the total area---consists of semiarid low plateaus, plains, and hills. Much of this region is sparsely populated and has a desolate appearance.
An elevated plateau and mountain region in the southwest, called the Kenya Highlands, is the heart of the nation, containing the bulk of Kenya's population and farmland. Much of the land lies 5,000 to 10,000 feet (1,500 to 3,000 m) above sea level and is dotted by extinct volcanoes. Among them are 17,058-foot (5,199-m) Mount Kenya, the highest mountain in Kenya, and Mount Elgon, which rises to a height of 14,178 feet (4,321 m) on the Uganda border. In the Aberdare Range north of Nairobi, Kenya's capital, peaks crest at more than 13,000 feet (4,000 m).
One arm of Africa's Great Rift Valley cuts through western Kenya. In many localities, especially in the highlands, it forms a steepsided trench 30 to 40 miles (48 to 64 km) wide and 2,000 to 3,000 feet (600 to 900 m) deep.
Most lakes, including Kenya's largest body of water, Lake Turkana, occur in the Great Rift Valley, where there is no outward drainage. A small section of Lake Victoria juts into the southwest. The adjoining shore is one of the most tropically humid parts of the country. Tips of Lake Stefanie, in the north, and Lake Natron, in the south, belong to Kenya.
Principal rivers are the Tana and the Galana-Athi, which flow from the highlands to the Indian Ocean. Smaller rivers include the Nzoia and Mara, both of which empty into Lake Victoria. Elsewhere, especially in the north and east, streams are intermittent, flowing only occasionally or during part of the year.
Although Kenya lies on the Equator, its climate varies considerably in temperature and precipitation. To a large extent, temperatures are governed by elevation. Mombasa, a port city on the Indian Ocean, has temperatures near 80° F. (27° C.) throughout the year. Nairobi, in contrast, some 5,500 feet (1,700 m) above sea level in the highlands, has average temperatures of 60° to 65° F. (16° to 18° C.) and has much greater temperature variations from night to day.
Rain is abundant along the coast; normally about 35 to 50 inches (890 to 1,270 mm) fall each year, depending on location. Similar amounts fall throughout the highlands, though several of the higher areas and the shore of Lake Victoria receive considerably more. Northern Kenya and the interior areas of the east are quite dry. Parts of the north receive less than 10 inches (250 mm) a year, and desertlike conditions occur.
Kenya is primarily a grassland, consisting of savannas and steppes. The savannas are generally tall-grass areas with small, thorny trees growing singly or in patches. The steppes, which receive less rain, usually lack trees and often have only a scant covering of grass. Forests are found mainly in scattered localities along the coast and in the loftier, more humid parts of the highlands. Few of the forests form dense growths.
Kenya is richly endowed with animal life. Big game, including elephants, rhinoceroses, lions, giraffes, zebras, and wildebeests, are among the more notable animals. There is also an abundance of small mammals, birds, fish, reptiles, and insects. Because of human encroachments, many of the animals are decreasing in number. To protect them, Kenya's government maintains numerous parks and game conservation areas. Amboseli and Tsavo national parks hold some of the largest concentrations of big game in East Africa.