Average Precipitation: According to the data (WorldClim 2.0)used for the study the average precipitation ranges from 1 to 682. The lowest precipitation is for the month of December and the highest precipitation is for the month of July. In the map above we can see that winter months (January, December) have low precipitation this is as the monsoon winds retreat and moves south –east. It is due to the change in pressure conditions caused by shift in sun rays towards Equator from Tropic of Cancer.

Spatial variation can be seen where districts such as Kishanganj receive high precipitation and Arwal receives low precipitation. 

Spatial variation in average precipitation in Bihar: This is a difference map between May and December we can see that north eastern regions are cold and receive high rainfall. The southern part is hot and dry.