If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Amherst: The hottest months are usually July and August with an average temp of 62°F, while the coldest months are February and January with an average of 25°F. The snowiest months in Amherst are February, January, March, and November, with each month seeing an average of 36 inches of snowfall.