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
Caseyville's weather in December involves a decrease in the average high-temperature, moving down from November's cool 52.9°F (11.6°C) to a wintry 41.9°F (5.5°C). December is noted for a mean low-temperature of 30°F (-1.1°C).Humidity
In Caseyville, Illinois, the average relative humidity in December is 77%.Rainfall
In Caseyville, during December, the rain falls for 8.4 days and regularly aggregates up to 2.2" (56mm) of precipitation. In Caseyville, during the entire year, the rain falls for 149.9 days and collects up to 33.94" (862mm) of precipitation.Snowfall
Months with snowfall are January through March, September, November and December. In Caseyville, in December, during 3.8 snowfall days, 1.73" (44mm) of snow is typically accumulated. In Caseyville, during the entire year, snow falls for 20.7 days and aggregates up to 7.13" (181mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:59 am and sunset at 4:39 pm. On the last day of December, sunrise is at 7:17 am and sunset at 4:49 pm CST.
Sunshine
The average sunshine in December is 4.8h.UV index
The months with the lowest UV index in Caseyville are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Boost your sun resistance with garments that are densely woven yet spacious. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
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?
How many days does it rain in December?
How many days 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?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Caseyville, IL
- Average high temperature in December: 41.9°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Caseyville, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Caseyville, IL
- Average wind speed in December: 8.8mph
The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).
Average humidity in December
Caseyville, IL
- Average humidity in December: 77%
The months with the highest relative humidity are May, July and August (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Caseyville, IL
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (1.77").
Average rainfall days in December
Caseyville, IL
- Average rainfall days in December: 8.4 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in December
Caseyville, IL
- Average snowfall in December: 1.73"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in December
Caseyville, IL
- Average snowfall days in December: 3.8 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Caseyville, IL
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in December
Caseyville, IL
- Average sunshine days in December: 18.6 days
The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is May (11.6 days).
Average UV index in December
Caseyville, IL
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Caseyville, IL
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in December
Caseyville, 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).
Caseyville, Illinois, USA
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