Weather can make or break a roadtrip, so here's some data about year-round temperatures in Nyaungdon to help you plan yours: The hottest months are usually April and March with an average temp of 85°F, while the coldest months are January and February with an average of 80°F. The rainiest months in Nyaungdon are July, August, June, and September, with each month seeing an average of 20 inches of rainfall.