Weather will likely play an important role when you plan your trip to Watson Lake, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and June with an average temp of 55°F, while the coldest months are December and January with an average of 4°F. The snowiest months in Watson Lake are January, November, December, and February, with each month seeing an average of 13 inches of snowfall.