Weather is probably a major factor when you plan your trip to Muzaffarpur, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May with an average temp of 88°F, while the coldest months are January and December with an average of 69°F. The rainiest months in Muzaffarpur are July, August, September, and June, with each month seeing an average of 13 inches of rainfall.