Silos and Smokestacks National Heritage Area - Operating Hours & Seasons (U.S. National Park Service)

Iowa experiences a climate with extremes of both heat and cold. The average annual temperature at Des Moines is 50°F (10°C) while for some locations in the north the figure is under 45°F. Winters are brisk and snowfall common, the capital receiving an average of 36.3 inches per season. Spring ushers in the beginning of the severe weather season, as well as bringing increased precipitation and warming temperatures. The Iowan summer is known for heat and humidity, with daytime temperatures sometimes exceeding 100°F (37.8°C).