December weather forecastGlen Ellyn, IL
December
Weather in December
December, the first month of the winter in Glen Ellyn, is still a cold month, with an average temperature fluctuating between 34.3°F (1.3°C) and 24.3°F (-4.3°C).Temperature
Onset of December witnesses a reduction in the average high-temperature, falling from a frosty 45.5°F (7.5°C) in November to an icy 34.3°F (1.3°C). Glen Ellyn experiences a consistent average temperature of 24.3°F (-4.3°C) throughout the nights in December.Humidity
The average relative humidity in December in Glen Ellyn is 81%.Rainfall
The months with the least rainfall are November and December Rain falls for 7.8 days and accumulates 1.65" (42mm) of rain.Snowfall
Months with snowfall in Glen Ellyn are January through May, October through December. In Glen Ellyn, during December, snow falls for 9.7 days and regularly aggregates up to 3.03" (77mm) of snow. Throughout the year, there are 47 snowfall days, and 20.2" (513mm) of snow is accumulated.Daylight
December has the shortest days of the year, 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 4:22 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:31 pm CST.
Sunshine
In December, the average sunshine in Glen Ellyn is 4.1h.UV index
In Glen Ellyn, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. 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
Average temperature in December
Glen Ellyn, IL
- Average high temperature in December: 34.3°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28°F).
- Average low temperature in December: 24.3°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (16.7°F).
Average pressure in December
Glen Ellyn, 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
Glen Ellyn, IL
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Glen Ellyn, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Glen Ellyn, IL
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is May (4.45").
The driest months (with the least rainfall) are November and December (1.65").
Average rainfall days in December
Glen Ellyn, IL
- Average rainfall days in December: 7.8 days
The month with the highest number of rainy days is July (20.1 days).
The month with the least rainy days is February (5.8 days).
Average snowfall in December
Glen Ellyn, IL
- Average snowfall in December: 3.03"
The month with the highest snowfall is January (5.87").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Glen Ellyn, IL
- Average snowfall days in December: 9.7 days
The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Glen Ellyn, 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: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Glen Ellyn, IL
- Average sunshine days in December: 15.7 days
The month with the most sunshine days is November (16.1 days).
The month with the least sunshine days is July (8.2 days).
Average UV index in December
Glen Ellyn, IL
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Glen Ellyn, 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 August and September (Cloud cover 32).
Average visibility in December
Glen Ellyn, IL
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
