Typical Weather in Decatur;, IL in December
40° F Avg High
24° F Avg Low
5 Rainy Days
☀️ Temperature Summary
Highs in December are typically around 40°F, which is cooler than usual in Decatur;. Pack a jacket if you're considering a visit to Decatur; at this time. You can expect overnight lows near 24°F most days. Temperatures will usually fall as the month goes on, with daily high temperatures ranging between 46°F and 37°F.
You may want to consider a warmer month to visit Decatur;, unless you're ready to brave the cold. If you're looking to travel when it's warmer, you might consider visiting in November instead, when daily highs are typically closer to 52°.
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 17% chance of rain for any given day in December. It's one of the drier months of the year for Decatur;, with total rainfall for the month around 3 inches.
Rainfall Throughout the Year
Planning a trip to Decatur;? Try our free trip weather planner