Niger River Basin Rainfall in Average Year

The majority of the rain falls during the rainy season that occurs during tropical summer. The Sahelian sub-desert zone by Timbuktu receives about 250 mm/yr, where as the basin as a whole received roughly 770mm/yr. This difference is a reflection of the patchiness of the rainfall of this basin. As the river flow eastwards towards the arid desert flow decreases as a result of low rainfall and high evaporation rates. The inland delta is an area of infiltration and high evaporation both of which decrease flow in the river, only the combined input from tributaries downstream of the inland delta allows the Niger river to grow to a larger river and reach the Gulf of Guinea.

Average Total Rainfall (mm/yr)

Bargraph referencing the colours on the rainfall maps.

Other Niger Maps

Niger Rainfall Maps