Climate almanac
St. Charles
Illinois, United States · 41.91°, -88.31°
What is the weather like in St. Charles in August?
In August, St. Charles is typically 82°F (28°C) during the day and 64°F (18°C) at night. The month brings about 3.6 in (92 mm) of precipitation in total.
- Average high82°F (28°C)
- Average low64°F (18°C)
- Precipitation3.6 in (92 mm)
- Clear or mostly clear days12
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)