If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Mengla County: The hottest months are usually April and May with an average temp of 75°F, while the coldest months are January and December with an average of 63°F. The rainiest months in Mengla County are August, July, June, and September, with each month seeing an average of 11 inches of rainfall.