The most pleasant months of the year for Belknap are June, September and July. In Belknap, there are 2 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for Belknap with an average high temperature of 86.3°, which ranks it as warmer than most places in Montana. December is the snowiest month in Belknap with 15.0 inches of snow, and 5 months of the year have significant snowfall. Days with noticeable humidity are rare throughout the year.