Typical Weather in Mount Vernon, IL in December
43° F Avg High
25° F Avg Low
6 Rainy Days
☀️ Temperature Summary
Highs in December are typically around 43°F, which is cooler than usual in Mount Vernon. You can expect overnight lows near 25°F most days. Temperatures will usually fall as the month goes on, with daily high temperatures ranging between 48°F and 41°F.
December is a great time to visit Mount Vernon, with mild temperatures and sunny days being very common.
High Temps Throughout the Year
🎒 What to Pack
Pick up a few of these items to keep your trip fun and comfortable.
☔ Rain Summary
You can expect about a 19% chance of rain for any given day in December. It's one of the drier months of the year for Mount Vernon, with total rainfall for the month around 3 inches.
Rainfall Throughout the Year
Planning a trip to Mount Vernon? Try our free trip weather planner