The most pleasant months of the year for Johnson are June, August and July. In Johnson, there are 4 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Johnson with an average high temperature of 82.9°, which ranks it as warmer than most places in Minnesota. January is the snowiest month in Johnson with 8.9 inches of snow, and 7 months of the year have significant snowfall. But there some days when the humidity becomes unpleasant, especially in July and August.