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
December brings a drop in Union's average high-temperature, falling from a frosty 44.4°F (6.9°C) in November to a cold 32.5°F (0.3°C). During December, Union consistently records a temperature low averaging a subzero cold 22.3°F (-5.4°C).Humidity
In December, the average relative humidity in Union is 83%.Rainfall
In Union, during December, the rain falls for 8 days and regularly aggregates up to 1.57" (40mm) of precipitation. In Union, Illinois, during the entire year, the rain falls for 154.6 days and collects up to 30.31" (770mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Union, in December, snow falls for 10.2 days, with typically accumulated 2.8" (71mm) of snow. Throughout the year, there are 44.9 snowfall days, and 17.24" (438mm) of snow is accumulated.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:04 am and sunset at 4:22 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:32 pm CST.
Sunshine
The average sunshine in December in Union is 3.8h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index in Union, Illinois. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 1 in December converts into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December in Union?
What is the average humidity in December in Union?
How much does it rain in Union in December?
How much does it snow in Union in December?
What is the month with the shortest days in Union?
What is the average length of the day in December in Union?
When is the sunrise / sunset in December in Union?
How long on average sun shines in December in Union?
What is the month with the lowest UV index in Union?
What is the UV index reading in December in Union?
Average temperature in December
Union, IL
- Average high temperature in December: 32.5°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in December: 22.3°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (13.8°F).
Average pressure in December
Union, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Union, IL
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in December
Union, IL
- Average humidity in December: 83%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (76%).
Average rainfall in December
Union, IL
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is June (4.21").
The driest months (with the least rainfall) are February and November (1.5").
Average rainfall days in December
Union, IL
- Average rainfall days in December: 8 days
The month with the highest number of rainy days is July (19.3 days).
The month with the least rainy days is February (4.8 days).
Average snowfall in December
Union, IL
- Average snowfall in December: 2.8"
The month with the highest snowfall is January (5.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Union, IL
- Average snowfall days in December: 10.2 days
The month with the highest number of snowfall days is January (12.3 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
Union, IL
- Average daylight in December: 9h and 1min
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: 3h and 5min
The month with the most sunshine is July (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Union, IL
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (9.5 days).
Average UV index in December
Union, IL
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Union, IL
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 35).
Average visibility in December
Union, 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).
Union, Illinois, USA
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