Climate almanac
Chester
Illinois, United States · 37.91°, -89.82°
What is the weather like in Chester in September?
In September, Chester is typically 83°F (28°C) during the day and 62°F (17°C) at night. The month brings about 3.0 in (75 mm) of precipitation in total.
- Average high83°F (28°C)
- Average low62°F (17°C)
- Precipitation3.0 in (75 mm)
- Clear or mostly clear days15
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)