Normal weather for Illinois in December
It's cold in December in Illinois with an average temperature of 5°C. Temperatures this month range from a low of 1°C to a high of 8°C. At night, you can expect temperatures between -6°C and 0°C.
In December, there is an average of 55 mm of precipitation, spread over 8 days. Of the total precipitation, about 6,4 cm falls as snow in December. The wind speed is around 4 Bft, mostly coming from the Southwest.
Illinois in December |
New York | ||
|---|---|---|---|
 Average Temperature |
5°C | 9°C | |
 High Temp |
8°C | 12°C | |
| Low Temp |
1°C | 4°C | |
 Total Precipitation |
55 mm | 133 mm | |
| Rainy Days |
8 days | 17 days | |
 Total Snowfall |
6,4 cm | 9,7 cm | |
| Snowy Days |
3 days | 3 days | |
Start of December
The month of December starts in Illinois with cold temps, averaging around 7°C during the day and nights around -1°C. There’s little chance of precipitation. The weather’s mostly sunny and dry.
With the temperature difference between day and night, it’s smart to wear layers. During the day, wear a thick jacket, sweater, and long pants. For the evening and morning, we recommend a heavy winter coat, sweater, long pants, beanie, and gloves.
Mid December
By mid-December, daytime temps drop to around 6°C, with nights around -2°C. Not much precipitation expected during this period. It’s mostly dry and sunny.
Since it cools down at night, it’s a good idea to wear layers. During the day, wear a thick jacket, sweater, and long pants. For the evening and morning, we recommend a heavy winter coat, sweater, long pants, beanie, and gloves.
End of December
By the end of December, the average daytime temperature in Illinois is around 5°C, while nighttime temps are about -3°C. A shower might pop up, but overall, the weather will be dry and sunny. Wear a heavy winter coat, sweater, long pants, beanie, and gloves.
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UV index
The UV index is a maximum of 1 this month. That's a low value on the intensity scale of 1 to 11. The risk of sunburn is minimal at this time.
Temperature records for Illinois in December
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The climate in Illinois is based on weather data from . Other places, like New York City, Miami or Los Angeles, might have different weather. You can check out all destinations in Illinois to get the full picture of the climate.
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Daily Temperature in December in Illinois
This chart shows the average daily high and low temperatures in December for Illinois, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in December in Illinois
The chart below shows the average daily precipitation in December for Illinois, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for December, you can expect about 8 days of precipitation in Illinois.
Daily Snowfall in December in Illinois
This chart shows the average daily snowfall in December in Illinois, measured in centimeters. The bottom of the chart shows the days of the month. The data is based on historical measurements and gives an idea of the average snowfall in December.
Daily UV Index in December in Illinois
This chart shows the average daily UV index in December in Illinois, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in December in Illinois Over the Years
This chart shows the average temperature in December in Illinois, measured in degrees Celsius, over the past few years.
Total Precipitation in December in Illinois Over the Years
This chart shows the average precipitation in December in Illinois, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Snowfall in December in Illinois per year
This chart shows the average snowfall in December in Illinois, measured in centimeters, over the past few years.
Daily Climate in December for Illinois
Click on any day in December to get detailed info about the usual weather on that day in Illinois. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in December in Illinois
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Average Weather in Illinois by Month
Click on a month below to see detailed weather info for Illinois. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
