Climate almanac
O'Fallon
Illinois, United States · 38.59°, -89.91°
What is the weather like in O'Fallon in March?
In March, O'Fallon is typically 60°F (15°C) during the day and 40°F (5°C) at night. The month brings about 4.9 in (125 mm) of precipitation in total. Snowfall averages about 0.6 in (14 mm) over the month.
- Average high60°F (15°C)
- Average low40°F (5°C)
- Precipitation4.9 in (125 mm)
- Clear or mostly clear days9
- Snowfall0.6 in (14 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)