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
Onset of December witnesses a reduction in the average high-temperature, falling from a cool 50.4°F (10.2°C) in November to an icy 39.2°F (4°C). An average nighttime temperature of 28.4°F (-2°C) is witnessed throughout December.Humidity
In December, the average relative humidity is 79%.Rainfall
In December, the rain falls for 5.9 days. Throughout December, 0.67" (17mm) of precipitation is accumulated. In Shelbyville, during the entire year, the rain falls for 116.5 days and collects up to 11.54" (293mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In Shelbyville, in December, during 4 snowfall days, 0.67" (17mm) of snow is typically accumulated. In Shelbyville, during the entire year, snow falls for 19 days and aggregates up to 2.8" (71mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 6:56 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 4:41 pm CST.
Sunshine
The average sunshine in December is 4.5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December?
How many days 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?
When are sunrise and sunset in December?
How many hours of sunshine does Shelbyville have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Shelbyville, IL
- Average high temperature in December: 39.2°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (34.3°F).
- Average low temperature in December: 28.4°F
The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).
Average pressure in December
Shelbyville, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Shelbyville, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in December
Shelbyville, IL
- Average humidity in December: 79%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Shelbyville, IL
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is June (1.46").
The driest month (with the least rainfall) is February (0.55").
Average rainfall days in December
Shelbyville, IL
- Average rainfall days in December: 5.9 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in December
Shelbyville, IL
- Average snowfall in December: 0.67"
The month with the highest snowfall is February (0.83").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Shelbyville, IL
- Average snowfall days in December: 4 days
The month with the highest number of snowfall days is February (5.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Shelbyville, IL
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 3min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in December
Shelbyville, IL
- Average sunshine days in December: 22.1 days
The month with the most sunshine days is December (22.1 days).
The month with the least sunshine days is June (13.5 days).
Average UV index in December
Shelbyville, IL
- Average UV index in December: 2
The months with the highest UV index are 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
Shelbyville, IL
- Average cloud cover in December: 53
The months with the most cloud cover are January and February (Cloud cover 55).
The months with the least cloud cover are June and September (Cloud cover 30).
Average visibility in December
Shelbyville, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, September, October, November and December (6mi).
The month with the lowest visibility is August (5mi).
Shelbyville, Illinois, USA
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