If you're looking forward to lots of outings with your partner, check out these details about year-round temperatures in Lom Sak: The hottest months are usually April and March with an average temp of 82°F, while the coldest months are December and January with an average of 76°F. The rainiest months in Lom Sak are August, July, May, and September, with each month seeing an average of 18 inches of rainfall.