September in Peoria averages a daily high of 25.9°C with nights around 13.8°C. Expect roughly 7.1 wet days totalling 76.9mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Peoria is September.
Based on GENERAL WAYNE A. DOWNING INTERNATIONAL AIRPORT, IL US (8.5km), 1995–2024. 30 years of September data.