December weather forecastBannockburn, IL
December
Weather in December
December, the first month of the winter in Bannockburn, is also a wintry month, with an average temperature fluctuating between 26.2°F (-3.2°C) and 34.5°F (1.4°C).Temperature
The start of December comes with a reduction in the average high-temperature, receding from a frosty 45.5°F (7.5°C) in November to an icy 34.5°F (1.4°C). During the nights of December, Bannockburn records an average temperature of 26.2°F (-3.2°C), a minor drop from daytime peaks.Humidity
In December, the average relative humidity is 80%.Rainfall
December is the month with the least rainfall. Rain falls for 8.6 days and accumulates 1.3" (33mm) of precipitation.Snowfall
January through April, October through December are months with snowfall in Bannockburn. In Bannockburn, in December, snow falls for 9.1 days, with typically accumulated 2.05" (52mm) of snow. Throughout the year, there are 42.9 snowfall days, and 13.82" (351mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:01 am and sunset at 4:20 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:29 pm CST.
Sunshine
The average sunshine in December is 4.1h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for average individuals.Note: The maximum UV index of 1 during December leads to these instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Stay sun-safe with clothing that is both closely woven and worn loosely. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Bannockburn, IL
- Average high temperature in December: 34.5°F
The warmest month (with the highest average high temperature) is July (77.7°F).
The month with the lowest average high temperature is January (28.6°F).
- Average low temperature in December: 26.2°F
The months with the highest average low temperature are July and August (66.7°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Bannockburn, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Bannockburn, IL
- Average wind speed in December: 11.2mph
The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in December
Bannockburn, IL
- Average humidity in December: 80%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Bannockburn, IL
- Average rainfall in December: 1.3"
The wettest months (with the highest rainfall) are May and June (3.82").
The driest month (with the least rainfall) is December (1.3").
Average rainfall days in December
Bannockburn, IL
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (5.9 days).
Average snowfall in December
Bannockburn, IL
- Average snowfall in December: 2.05"
The month with the highest snowfall is January (4.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Bannockburn, IL
- Average snowfall days in December: 9.1 days
The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Bannockburn, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Bannockburn, IL
- Average sunshine days in December: 15.3 days
The month with the most sunshine days is December (15.3 days).
The month with the least sunshine days is April (10.8 days).
Average UV index in December
Bannockburn, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Bannockburn, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in December
Bannockburn, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





