Weather is probably a major factor when you plan your trip to Lumbini, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and April with an average temp of 88°F, while the coldest months are January and December with an average of 66°F. The rainiest months in Lumbini are July, August, September, and June, with each month seeing an average of 15 inches of rainfall.