Weather is probably a major factor when you plan your trip to Chewelah, 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 67°F, while the coldest months are December and January with an average of 28°F. The snowiest months in Chewelah are January, December, February, and March, with each month seeing an average of 6 inches of snowfall.