The most pleasant months of the year for Iowa are June, August and July. In Iowa, there are 3 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Iowa with an average high temperature of 81.2°, which ranks it as cooler than most places in North Dakota. January is the snowiest month in Iowa with 8.2 inches of snow, and 8 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.