Climate almanac
Collinsville
Illinois, United States · 38.67°, -89.98°
What is the weather like in Collinsville in August?
In August, Collinsville is typically 86°F (30°C) during the day and 68°F (20°C) at night. The month brings about 4.5 in (114 mm) of precipitation in total.
- Average high86°F (30°C)
- Average low68°F (20°C)
- Precipitation4.5 in (114 mm)
- Clear or mostly clear days12
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)