CLIMATE OVERVIEW. Iowa, Iowa, gets 35 inches of rain per year. The US average is 39. Snowfall is 30 inches. The average US city gets 26 inches of snow per year. The number of days with any measurable precipitation is 64. On average, there are 200 sunny days per year in Iowa, Iowa. The July high is around 84 degrees. The January low is 11. Sperling's comfort index for Iowa is a 32 out of 100, where a higher score indicates a more comfortable year-around climate. The US average for the comfort index is 54.