Ganges Brahmaputra River Basin Rainfall in Average Year

The rainfall distribution within the river basin is representative of the range of topography and climate of this area. The areas with least rainfall are located in the Himalayan mountain range and the Tibetan plateau. These two areas receive low rainfall but the glacier melt is an important input to the river system. As the Ganges River travels out of the mountains it crosses the Indian plains which is an arid area and lies in the rain shadow of the Himalayas. The lower reaches receive the highest rainfall, especially at the time of the monsoon which normally occurs during the months of July-October. As a consequence of this high rainfall flood conditions are common during the monsoon period. Outside of this period very little rain falls which results in flow levels dropping in the rivers.

Average Total Rainfall (mm/yr)

Bargraph referencing the colours on the rainfall maps.

Other Ganges Brahmaputra Maps

Ganges Brahmaputra Rainfall Maps