Weather can make or break a roadtrip, so we've gathered some data about year-round temperatures in Attapeu to help you plan yours. The hottest months are usually March and April with an average temp of 81°F, while the coldest months are January and December with an average of 75°F. The rainiest months in Attapeu are July, August, September, and June, with each month seeing an average of 22 inches of rainfall.