Weather will likely play an important role when you plan your trip to May, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August with an average temp of 62°F, while the coldest months are December and January with an average of 22°F. The snowiest months in May are February, January, December, and March, with each month seeing an average of 6 inches of snowfall.