Weather is probably a major factor when you plan your trip to Mongar, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and April with an average temp of 80°F, while the coldest months are January and December with an average of 68°F. The rainiest months in Mongar are June, July, August, and May, with each month seeing an average of 30 inches of rainfall.