When you’re planning your stay in Lan Mu Chay, year-round temperatures and rainfall may be important factors to consider. The hottest months are usually May and June with an average temp of 71°F, while the coldest months are January and December with an average of 58°F. The rainiest months in Lan Mu Chay are August, July, June, and September, with each month seeing an average of 13 inches of rainfall.