Rainfall

Rainfall is distributed very unevenly in Africa. Most areas receive either too much rain or too little. In parts of the West Coast, for example, annual rainfall averages more than 100 inches. In Monrovia, Liberia, an average of more 40 inches of rainfalls during the month of June alone.
In contrast more than half of Africa receives less than 20 inches of rainfall yearly. The Sahara and the Namib Desert receive an average of less than 10 inches a year. In parts of the deserts, rain may not fall for 6 or 7 years in a row. Then when it does rain, it is more destructive to both plant and animal life.
 Rain falls the year around in the forest of the Congo basin and the coastal regions of Western Africa. But almost all the rest of Africa has one or two seasons of heavy rainfall separated by dry periods. In some regions of Africa the amounts varies sharply from year to year rather than from season.
Since the late 1960s droughts have caused much suffering in Africa. Millions of Africans have died of starvation and related causes. The hardest hit areas include Ethiopia and the Sahel region on the Southern edge of the Sahara.
The dominant feature governing the climates of Africa is the fact that the Equator passes through the middle part of the continent.  This means that the sun is always overhead at noon in most parts of Africa.  Sunshine and warmth are enjoyed in abundance almost every where in Africa, but the distribution of precipitation is very uneven, evaporation rates are high and limitations in water supply are severe problem over wide areas of the continent.
Many of Africa’s climates can be explained by the movement of air masses, which differ from one another in their amount of moisture and their relative stability rather than their temperature.
These air masses meet in a region of low pressure which is referred to as the Inter tropical convergence zone (I T C Z).
In January the temperature increases and pressure is created in the Southern Hemisphere. This leads to high rainfall in the Southern Hemisphere except the Kalahari, more areas in South Africa, Zimbabwe, Zambia and Botswana receive more rain.
While in July the rain belts move northwards from earlier positions. The northern hemisphere is highly influenced by trade wind