Climate almanac
St. Charles
Illinois, United States · 41.91°, -88.31°
What is the weather like in St. Charles in September?
In September, St. Charles is typically 77°F (25°C) during the day and 58°F (14°C) at night. The month brings about 3.2 in (81 mm) of precipitation in total.
- Average high77°F (25°C)
- Average low58°F (14°C)
- Precipitation3.2 in (81 mm)
- Clear or mostly clear days14
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)