The most pleasant months of the year for Rockford are June, September and August. In Rockford, there are 2 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Rockford with an average high temperature of 85.5°, which ranks it as about average compared to other places in South Dakota. March is the snowiest month in Rockford with 8.0 inches of snow, and 8 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.