Weather is probably a major factor when you plan your trip to Frenchglen, 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 68°F, while the coldest months are December and January with an average of 31°F. The snowiest months in Frenchglen are January, February, March, and December, with each month seeing an average of 10 inches of snowfall.