Weather is only one factor, but it can really affect your travel plans, especially when you are planning a longer stay in Motihari. The hottest months are usually April and May with an average temp of 87°F, while the coldest months are January and December with an average of 68°F. The rainiest months in Motihari are July, August, September, and June, with each month seeing an average of 16 inches of rainfall.