If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Rusutsu: The hottest months are usually August and July with an average temp of 64°F, while the coldest months are January and February with an average of 24°F. The snowiest months in Rusutsu are January, February, March, and December, with each month seeing an average of 30 inches of snowfall.