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
Setting in of December comes with a decrease in the average high-temperature, moving from a frosty 45.5°F (7.5°C) in November to a wintry 34.2°F (1.2°C). Big Rock, during the nights of December, experiences an average temperature drop to a freezing cold 23.7°F (-4.6°C).Humidity
The average relative humidity in December is 82%.Rainfall
The month with the least rainfall is December, when the rain falls for 7.8 days and typically collects 1.57" (40mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 9.1 days. Throughout December, 2.64" (67mm) of snow is accumulated. In Big Rock, during the entire year, snow falls for 44.6 days and aggregates up to 15.2" (386mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:02 am and sunset at 4:24 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:33 pm CST.
Sunshine
The average sunshine in December is 4.1h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 1 in December translates into these instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Be vigilant! The reflective nature of snow can increase the Sun's UV radiation nearly twofold.
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 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 is the sunrise / sunset in December?
How many hours of sunshine does Big Rock have in December?
What are the months with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Big Rock, IL
- Average high temperature in December: 34.2°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in December: 23.7°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (15.8°F).
Average pressure in December
Big Rock, IL
- Average pressure in December: 30.1"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
Big Rock, IL
- Average wind speed in December: 9.1mph
The windiest months (with the highest average wind speed) are January, February and April (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Big Rock, IL
- Average humidity in December: 82%
The months with the highest relative humidity are January, July and August (84%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Big Rock, IL
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is May (4.33").
The driest month (with the least rainfall) is December (1.57").
Average rainfall days in December
Big Rock, IL
- Average rainfall days in December: 7.8 days
The month with the highest number of rainy days is July (18.2 days).
The month with the least rainy days is February (6 days).
Average snowfall in December
Big Rock, IL
- Average snowfall in December: 2.64"
The month with the highest snowfall is January (4.65").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Big Rock, IL
- Average snowfall days in December: 9.1 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
Big Rock, 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: 4h and 1min
The month with the most sunshine is August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Big Rock, IL
- Average sunshine days in December: 15.7 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.3 days).
Average UV index in December
Big Rock, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Big Rock, 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 34).
Average visibility in December
Big Rock, 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).
Big Rock, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location