The most pleasant months of the year for Sidney are June, September and August. In Sidney, there are 2 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Sidney with an average high temperature of 86.0°, which ranks it as warmer than most places in South Dakota. March is the snowiest month in Sidney with 8.3 inches of snow, and 8 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.