Ultraviolet radiation is the main source of energy for the photochemical reaction andrndynamics in the stratosphere and ionosphere. It is also one of the main sources of energyrnrequired for the evolution of animals and plants.rnThe method used to make people aware the risks related to UV is using a calculationrnof the amount of daily irradiance, which is called dose rate. This dose rate then isrnchanged to UV index (UVI). Erythermal UV radiation (UVery) is the integrated solarrnspectrum over the effective biological response to UV wavelengths on the groundrnbetween 295-400 nm. This effective biological response is called action spectrum. Thernaction spectrum is the normalized UV amount, which affects the health of animals andrnplants or biosphere in general. The value of UVI in Africa is 4 to 9, moderate to highrnoverall. This is due to the tropical nature of most parts of Africa. The trend of UVrnradiation in Africa shows significant decrease in the year from 1980 to 1992 and a slightrnincrease in recent years from 1997 to 2002. The ozone amount on the other hand isrnincreasing in Africa. The variability of ozone in tropical Africa is relatively stable. Thernaerosol index in Africa is generally decreasing. UV, aerosols and ozone do not showrnhigh seasonal variability in this part of the continent.rnThe study and understanding of UV and its determining factors in Africa hardlyrnexists. Here attempts are made to associate UV with these determining factors. UV andrnozone established 41% of the total variability in the surface UV in Africa. Clouds showrn31% variability in the surface UV and aerosols established only 7% total surface UVrndetermination