The most pleasant months of the year for Mountrail are July, August and June. In Mountrail, there are 3 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for Mountrail with an average high temperature of 81.0°, which ranks it as cooler than most places in North Dakota. January is the snowiest month in Mountrail with 8.6 inches of snow, and 8 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.