If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Eaton Rapids: The hottest months are usually July and August with an average temp of 68°F, while the coldest months are January and February with an average of 29°F. The snowiest months in Eaton Rapids are January, March, November, and October, with each month seeing an average of 8 inches of snowfall.