September in Iowa City averages a daily high of 25.4°C with nights around 12.1°C. Expect roughly 8.8 wet days totalling 72.1mm. Comfortable conditions for being outdoors all day.
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 September data.