September in Detroit averages a daily high of 24.1°C with nights around 14.1°C. Expect roughly 8.7 wet days totalling 70.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Detroit is August–September.
Based on DETROIT CITY AIRPORT, MI US (9km), 1995–2024. 28 years of September data.