Climate almanac
Fairfield
Illinois, United States · 42.22°, -88.06°
What is the weather like in Fairfield in September?
In September, Fairfield is typically 74°F (24°C) during the day and 61°F (16°C) at night. The month brings about 3.0 in (76 mm) of precipitation in total.
- Average high74°F (24°C)
- Average low61°F (16°C)
- Precipitation3.0 in (76 mm)
- Clear or mostly clear days13
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)