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
During the transition into December, Illinois City observes a decrease in the average high-temperature, falling from a frosty 47.1°F (8.4°C) in November to a wintry 34.5°F (1.4°C). An average nighttime temperature of 24.1°F (-4.4°C) is noted during the month of December.Humidity
In Illinois City, the average relative humidity in December is 81%.Rainfall
The month with the least rainfall is December, when the rain falls for 6.6 days and typically collects 0.75" (19mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Illinois City, in December, snow falls for 7.8 days, with typically accumulated 1.42" (36mm) of snow. In Illinois City, during the entire year, snow falls for 35.4 days and aggregates up to 8.35" (212mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of December in Illinois City, sunrise is at 7:10 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:44 pm CST.
Sunshine
In December, the average sunshine is 4.4h.UV index
In Illinois City, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 2 in December translates into these instructions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
What is the driest month?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days in Illinois City?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Illinois City have in December?
What is the UV index intensity in December?
Average temperature in December
Illinois City, IL
- Average high temperature in December: 34.5°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 (28.2°F).
- Average low temperature in December: 24.1°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in December
Illinois City, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Illinois City, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in December
Illinois City, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Illinois City, IL
- Average rainfall in December: 0.75"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is December (0.75").
Average rainfall days in December
Illinois City, IL
- Average rainfall days in December: 6.6 days
The month with the highest number of rainy days is June (17 days).
The month with the least rainy days is January (4.2 days).
Average snowfall in December
Illinois City, IL
- Average snowfall in December: 1.42"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Illinois City, IL
- Average snowfall days in December: 7.8 days
The month with the highest number of snowfall days is January (10.3 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
Illinois City, 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 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in December
Illinois City, IL
- Average sunshine days in December: 18.6 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in December
Illinois City, IL
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Illinois City, IL
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
Illinois City, 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).
Illinois City, Illinois, USA
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