Climate almanac
Monticello
Illinois, United States · 40.03°, -88.57°
What is the weather like in Monticello in December?
In December, Monticello is typically 43°F (6°C) during the day and 28°F (-2°C) at night. The month brings about 2.4 in (62 mm) of precipitation in total. Snowfall averages about 2.2 in (57 mm) over the month.
- Average high43°F (6°C)
- Average low28°F (-2°C)
- Precipitation2.4 in (62 mm)
- Clear or mostly clear days7
- Snowfall2.2 in (57 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)