Climate almanac
O'Fallon
Illinois, United States · 38.59°, -89.91°
What is the weather like in O'Fallon in April?
In April, O'Fallon is typically 69°F (20°C) during the day and 48°F (9°C) at night. The month brings about 5.7 in (145 mm) of precipitation in total. Snowfall averages about 0.2 in (6 mm) over the month.
- Average high69°F (20°C)
- Average low48°F (9°C)
- Precipitation5.7 in (145 mm)
- Clear or mostly clear days10
- Snowfall0.2 in (6 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)