Kilimanjaro is a large stratovolcano composed of three distinct volcanic cones: Kibo, the highest; Mawenzi at 5,149 metres (16,893 ft) and Shira, the lowest at 4,005 metres (13,140 ft). Mawenzi and Shira are extinct, while Kibo is dormant and could erupt again.
Uhuru Peak is the highest summit on Kibo’s crater rim. The Tanzania National Parks Authority, a Tanzanian government agency and the United Nations Educational, Scientific and Cultural Organization lists the height of Uhuru Peak as 5,895 m (19,341 ft), based on a British survey in 1952. The height has since been measured as 5,892 metres (19,331 ft) in 1999, 5,902 metres (19,364 ft) in 2008, and 5,899 metres (19,354 ft) in 2014.
The climate of Kilimanjaro is influenced by the height of the mountain, which allows the simultaneous influence of the equatorial trade winds and the high altitude anti-trades; and by the isolated position of the mountain. Kilimanjaro has daily upslope and nightly downslope winds, a regimen stronger on the southern than the northern side of the mountain. The flatter southern flanks are more extended and affect the atmosphere more strongly.
Kilimanjaro has two distinct rainy seasons, one from March to May and another around November. The northern slopes receive much less rainfall than the southern ones. The lower southern slope receives 800 to 900 millimetres (31 to 35 in) annually, rising to 1,500 to 2,000 millimetres (59 to 79 in) at 1,500 metres (4,900 ft) altitude and peaking “partly over” 3,000 millimetres (120 in) in the forest belt at 2,000 to 2,300 metres (6,600 to 7,500 ft). In the alpine zone, annual precipitation decreases to 200 millimetres (7.9 in).
Sailors’ reports recorded by Ptolemy mention a “moon mountain” and a spring lake of the Nile, which may indicate Kilimanjaro; although available historical information does not allow differentiation among others in East Africa like Mount Kenya, the mountains of Ethiopia, the Virunga Mountains, the Rwenzori Mountains, and Kilimanjaro. Before Ptolemy, Aeschylus and Herodotus referred to “Egypt nurtured by the snows” and to a spring between two mountains, respectively. One of these mentions two tall mountains in the coastal regions with a valley with traces of fire between. Martín Fernández de Enciso, a Spanish traveller to Mombasa who obtained information about the interior from native caravans, said in his Summa de Geografía (1519) that west of Mombasa “stands the Ethiopian Mount Olympus, which is exceedingly high, and beyond it are the Mountains of the Moon, in which are the sources of the Nile”.
According to reports gathered in the 19th century from the Maasai, Lake Chala on Kibo’s eastern flank was the site of a village that was destroyed by an eruption.