If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Pyin Oo Lwin: The hottest months are usually April and March with an average temp of 76°F, while the coldest months are January and December with an average of 64°F. The rainiest months in Pyin Oo Lwin are August, July, June, and September, with each month seeing an average of 18 inches of rainfall.