If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Tsubame: The hottest months are usually August and July with an average temp of 73°F, while the coldest months are February and January with an average of 38°F. The rainiest months in Tsubame are December, July, January, and November, with each month seeing an average of 8 inches of rainfall.