If you're looking forward to lots of outings with your partner, check out these details about year-round temperatures in Thanh Hoa: The hottest months are usually June and July with an average temp of 84°F, while the coldest months are January and December with an average of 67°F. The rainiest months in Thanh Hoa are August, September, July, and October, with each month seeing an average of 12 inches of rainfall.