Climate almanac
Belleville
Illinois, United States · 38.52°, -89.98°
What is the weather like in Belleville in September?
In September, Belleville is typically 83°F (28°C) during the day and 62°F (17°C) at night. The month brings about 3.4 in (86 mm) of precipitation in total.
- Average high83°F (28°C)
- Average low62°F (17°C)
- Precipitation3.4 in (86 mm)
- Clear or mostly clear days15
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)