Climate almanac
Chillicothe
Illinois, United States · 40.92°, -89.49°
What is the weather like in Chillicothe in September?
In September, Chillicothe is typically 80°F (27°C) during the day and 59°F (15°C) at night. The month brings about 2.6 in (65 mm) of precipitation in total.
- Average high80°F (27°C)
- Average low59°F (15°C)
- Precipitation2.6 in (65 mm)
- Clear or mostly clear days15
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)