Climate is the average weather conditions for a place recorded for a long period of time usually 35yrs. In East Africa, there are four major types of climatic zones which are; Tropical/equatorial climate, Savannah climate, Desert/semi-arid climate, and montane climate. Climate influences human activities e.g. agriculture, settlement, feeding, dressing, and other physical aspects like vegetation.
Factors influencing the climate of East Africa
- Altitude: Climate changes with height above sea level. Areas near mountains receive heavy rainfall and low temperature especially on the windward side e.g. Mt. Kenya, Elgon, Kilimanjaro. Altitude also influences temperature differences e.g. areas on a higher altitude are cooler e.g. Nairobi, Kabale and Kampala while lowland areas receive high temperate e.g. Mombasa and Kasese.
- Distance from the sea: Areas close to water bodies receive heavy and reliable rainfall e.g. shores of Lake Victoria (Kisumu, Entebbe, Bukoba, Mwanza and Nyanza province). This is due to the abundant moisture released into the atmosphere through evaporation whereas areas which are far away from water bodies receive low and unreliable rainfall and hot temperature due to less moisture release e.g. Dodoma, Karamoja and Masailand.
- Latitude: Climate changes as one moves away from the equator, North or south. The equator influences the occurrence of the Inter-Tropical Convergence Zone (ITCZ). This is in relation to apparent movement of the over head sun. Areas around the equator receive double maxima of rainfall and hot temperature between February and May and between September and November e.g. Entebbe, Kisumu while areas that are far away from the equator receive single maxima of rainfall e.g. Gulu and Dodoma.
- Relief: Highland areas act as barriers to prevailing winds. In such areas, there are differences between the conditions on the lee ward side and the wind ward side. The leeward side receives little or no rainfall because its in the rain shadow e.g. Kasese and Arusha while areas on the wind ward side receive heavy rainfall and lower temperatures e.g. Mbale and Kigezi region.
- Vegetation: Areas with tropical rainforests receive heavy rainfall due to abundant moisture release through evapo-transpiration e.g. near Mabira forest in Mukono district while areas without vegetation cover receive hot temperatures and low rainfall e.g. Kondoa region (Miombo woodlands), Machakos, Turkana land and Karamoja.
- Influence of man: Due to man’s activities such as bush burning, swamp reclamation and deforestation, this leads to disappearance of vegetation hence low rainfall and high temperature. Urbanisation through industrialisation and road construction has also led to global warming hence hot temperatures in cities e.g. Kampala and Dodoma. Activities such as afforestation and re-afforestation have led to growth of vegetation hence leading to heavy rainfall.
- Influence of local trade winds: Trade winds have got an impact especially along the coastal areas and shoes of Lake Victoria. They lead to formation of land and sea breezes.