Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
In Millbrook, the beginning of December is marked by a lowered average high-temperature, shifting from November's frosty 45.9°F (7.7°C) to an icy 34.2°F (1.2°C). During December, Millbrook's temperature averages to a freezing cold 23.9°F (-4.5°C) at night.Humidity
The average relative humidity in December is 82%.Rainfall
In Millbrook, during December, the rain falls for 8.2 days and regularly aggregates up to 1.85" (47mm) of precipitation. Throughout the year, there are 168.3 rainfall days, and 35.47" (901mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. In Millbrook, in December, during 10.2 snowfall days, 2.87" (73mm) of snow is typically accumulated. In Millbrook, during the entire year, snow falls for 47.1 days and aggregates up to 16.61" (422mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 7:02 am and sunset at 4:24 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:34 pm CST.
Sunshine
The average sunshine in December is 4.2h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 1 during December leads to these instructions:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December in Millbrook?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Millbrook, IL
- Average high temperature in December: 34.2°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in December
Millbrook, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Millbrook, IL
- Average wind speed in December: 9.1mph
The windiest months (with the highest average wind speed) are January and April (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Millbrook, IL
- Average humidity in December: 82%
The months with the highest relative humidity are July and August (84%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Millbrook, IL
- Average rainfall in December: 1.85"
The wettest month (with the highest rainfall) is May (4.88").
The driest month (with the least rainfall) is November (1.73").
Average rainfall days in December
Millbrook, IL
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (20.3 days).
The month with the least rainy days is February (6 days).
Average snowfall in December
Millbrook, IL
- Average snowfall in December: 2.87"
The month with the highest snowfall is January (4.88").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Millbrook, IL
- Average snowfall days in December: 10.2 days
The month with the highest number of snowfall days is January (13.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Millbrook, IL
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 1min
The months with the most sunshine are June and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Millbrook, IL
- Average sunshine days in December: 14.5 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is July (7.2 days).
Average UV index in December
Millbrook, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Millbrook, IL
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).
Average visibility in December
Millbrook, IL
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Millbrook, Illinois, USA
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