August in Iowa City averages a daily high of 28.6°C with nights around 17.1°C. Expect roughly 9.6 wet days totalling 91mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Iowa City is August–October.
Based on IOWA CITY MUNICIPAL AIRPORT, IA US (2.7km), 1995–2024. 30 years of August data.