Mali is located in western Africa at a latitudes of 10 to 25°N, straddling the sub‐tropical band called the Sahel. The northern parts of Mali reach well into the dry Sahara desert, while the southern regions experience a wetter, more tropical, climate.
The seasonal rainfalls in Mali are controlled by the movement of the tropical rain belt (also known as the Inter‐Tropical Conversion Zone, ITCZ) which oscillates between the northern and southern tropics over the course of a year, and brings rainfall to the southern regions of Mali when it is in its northern position between June and October, peaking in August. The average rainfall in the wettest (southernmost) regions at this time is an average 300mm per month, but rainfall totals diminish rapidly with increasing latitude. In the dry months between November and March, almost no rain falls at all. Variations in the latitudinal movements of the ITCZ from one year to another cause large inter‐annual variability in wet‐season rainfall, which means that Mali suffers from recurring drought. The northern, desert regions of Mali receive very little rainfall all year round.
Source: University of Oxford, School of Geography and the Environment. Accessed on 23 November 2009 at: http://country-profiles.geog.ox.ac.uk/.