The most pleasant months of the year for Keller are August, July and June. In Keller, there are 3 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Keller with an average high temperature of 80.8°, which ranks it as cooler than most places in North Dakota. January is the snowiest month in Keller with 7.6 inches of snow, and 8 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.