If you're hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Lop Buri: The hottest months are usually April and March with an average temp of 87°F, while the coldest months are December and January with an average of 79°F. The rainiest months in Lop Buri are September, August, October, and July, with each month seeing an average of 9 inches of rainfall.