If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Uwamachi: The hottest months are usually August and July with an average temp of 71°F, while the coldest months are January and February with an average of 34°F. The rainiest months in Uwamachi are September, August, July, and October, with each month seeing an average of 8 inches of rainfall.