Illinois (Chicago)
December
Weather in Illinois for December 2026
Your guide to Illinois weather in December - trends and predictions
With an average of 2 snowy days, Illinois usually enjoys a light touch of snow in December.
In general, the average temperature in Illinois at the beginning of December is 3.6 °C. As the month progressed, temperatures tended to slightly decrease, reaching an average of 3.4 °C by the end of December.
Illinois experiences moderate rainfall in December, with an average of 7 rainy days and a total precipitation of 82.4 mm.
Is December a good time to visit Illinois? check out the best time to travel to Illinois page.
✨ Is December a good time to visit Illinois? – Ask the AI Weatherman
Snow Forecast ❄️
Temperatures
Rain 🌧️
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22
Dry days
7
Rainy days
2
Snow days
3°/-1°
Temperatures
24 km/h
Avg max wind
75 %
Avg humidity
Illinois Weather December
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What’s the Weather Like in Illinois This December?
Discover the average temperatures and weather trends across Illinois’s cities this December.
Temperatures trend during December in Illinois
See the weather trend as well as the moving average line
December weather in Illinois day by day
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| Date | Weather | Temperatures | Rain | Snow | More |
|---|---|---|---|---|---|
| Dec. 1 |  Light snow | 3° /-2° | 5.3 mm | 1.6 cm | |
| Dec. 2 |  Patchy rain possible | 5° /0° | 1 mm | 0.2 cm | |
| Dec. 3 |  Light rain | 5° /-1° | 4.8 mm | 0.8 cm | |
| Dec. 4 |  Overcast | 2° /-3° | 0 mm | 0 cm | |
| Dec. 5 | Light rain | 3° /-3° | 3.7 mm | 0.3 cm | |
| Dec. 6 | Overcast | 3° /-2° | 0 mm | 0 cm | |
| Dec. 7 | Light snow | 5° /-1° | 1.4 mm | 1 cm | |
| Dec. 8 | Overcast | 3° /1° | 0.1 mm | 0 cm | |
| Dec. 9 | Light rain | 6° /1° | 3 mm | 0 cm | |
| Dec. 10 | Light rain | 6° /1° | 4.2 mm | 0 cm | |
| Dec. 11 | Light rain | 4° /-1° | 2.5 mm | 0 cm | |
| Dec. 12 | Light rain | 3° /-1° | 8 mm | 0.7 cm | |
| Dec. 13 | Light snow | 3° /-2° | 1.5 mm | 1 cm | |
| Dec. 14 | Light rain | 3° /-2° | 5.7 mm | 0 cm | |
| Dec. 15 | Light rain | 5° /0° | 4.4 mm | 0 cm | |
| Dec. 16 | Patchy rain possible | 5° /0° | 2.2 mm | 0 cm | |
| Dec. 17 | Overcast | 2° /0° | 0.3 mm | 0 cm | |
| Dec. 18 | Patchy rain possible | 2° /-2° | 1.7 mm | 0.3 cm | |
| Dec. 19 | Overcast | 0° /-4° | 0 mm | 0 cm | |
| Dec. 20 | Overcast | 3° /-2° | 0 mm | 0 cm | |
| Dec. 21 | Patchy rain possible | 2° /-2° | 0.2 mm | 0 cm | |
| Dec. 22 | Light rain | 3° /-3° | 3 mm | 0.5 cm | |
| Dec. 23 | Patchy rain possible | 2° /-2° | 1.1 mm | 0 cm | |
| Dec. 24 | Overcast | 2° /-3° | 0.1 mm | 0 cm | |
| Dec. 25 | Patchy rain possible | 2° /-2° | 1.9 mm | 0 cm | |
| Dec. 26 |  Sunny | 3° /-2° | 0.5 mm | 0 cm | |
| Dec. 27 | Light rain | 5° /1° | 3.6 mm | 0 cm | |
| Dec. 28 | Light rain | 6° /2° | 9.1 mm | 0 cm | |
| Dec. 29 | Light snow | 4° /-1° | 2.4 mm | 1 cm | |
| Dec. 30 | Light snow | 4° /-2° | 2.3 mm | 1 cm | |
| Dec. 31 | Light snow | 2° /-2° | 8.3 mm | 3.3 cm | |
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Important Notice
Our weather forecast for Illinois in December is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Illinois forecast closer to your planned date for the most up-to-date weather information.
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Illinois in December - FAQ
What are the expected maximum and minimum temperatures in Illinois during December?
Brace for cold days with temperatures not exceeding 3° and nights that are likely to be freezing. Winter clothing is essential for comfort and safety.
How much rainfall should be expected in Illinois during December?
Moderate rainfall is anticipated in Illinois during December, with a total of 82.4 mm spread over approximately 7 days. Considering plans for rainy days is advisable.
Will it snow in Illinois in December 2026?
Illinois experiences an average snowfall of 11.7 cm during December, occurring over 2 days.
What are the typical wind conditions in Illinois during December?
The average wind speed in Illinois during December is 24 km/h, suggesting breezy to windy conditions, depending on your activities.
Illinois snow forecast December 2026
Track daily snowfall levels and discover Illinois’s snowy potential this December ❄️
On average, Illinois sees 2 snowy days during December, with approximately 11.7 cm of total snowfall.
December rainfall patterns in Illinois
Explore the daily rainfall trends and prepare for Illinoiss December weather 💧
Typically, Illinois has 7 rainy days in December with a total of 82.4 mm of rainfall.
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