Weather can make or break a roadtrip, so we've gathered some data about year-round temperatures in Mosby to help you plan yours. The hottest months are usually July and August with an average temp of 69°F, while the coldest months are February and December with an average of 28°F. The snowiest months in Mosby are October, April, February, and March, with each month seeing an average of 7 inches of snowfall.