December weather forecastRockbridge, IL
December
Weather in December
The first month of the winter, December, is still a cold month in Rockbridge, Illinois, with an average temperature fluctuating between 40.5°F (4.7°C) and 28.6°F (-1.9°C).Temperature
December brings a decrease in the average high-temperature, shifting from a cool 51.6°F (10.9°C) in November to an icy 40.5°F (4.7°C). Rockbridge temperatures generally rest at a low of 28.6°F (-1.9°C) during the December nights.Humidity
In Rockbridge, the average relative humidity in December is 77%.Rainfall
In Rockbridge, during December, the rain falls for 6.4 days and regularly aggregates up to 0.75" (19mm) of precipitation. In Rockbridge, during the entire year, the rain falls for 120.6 days and collects up to 14.17" (360mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In Rockbridge, in December, snow falls for 3.7 days, with typically accumulated 0.83" (21mm) of snow. Throughout the year, there are 19.1 snowfall days, and 3.82" (97mm) of snow is accumulated.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year in Rockbridge.On the first day of December, sunrise is at 7:02 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:47 pm CST.
Sunshine
In Rockbridge, Illinois, the average sunshine in December is 4.9h.UV index
The months with the lowest UV index in Rockbridge are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: An average maximum UV index of 2 in December leads to these recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rockbridge, IL
- Average high temperature in December: 40.5°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (35.2°F).
- Average low temperature in December: 28.6°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (22.3°F).
Average pressure in December
Rockbridge, 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 (29.91"Hg).
Average wind speed in December
Rockbridge, IL
- Average wind speed in December: 9.2mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in December
Rockbridge, IL
- Average humidity in December: 77%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Rockbridge, IL
- Average rainfall in December: 0.75"
The wettest month (with the highest rainfall) is June (1.93").
The driest month (with the least rainfall) is November (0.67").
Average rainfall days in December
Rockbridge, IL
- Average rainfall days in December: 6.4 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (5.6 days).
Average snowfall in December
Rockbridge, IL
- Average snowfall in December: 0.83"
The month with the highest snowfall is February (1.34").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Rockbridge, IL
- Average snowfall days in December: 3.7 days
The month with the highest number of snowfall days is January (6 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
Rockbridge, IL
- Average daylight in December: 9h and 30min
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 30min).
- Average sunshine in December: 4h and 54min
The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in December
Rockbridge, IL
- Average sunshine days in December: 21.7 days
The month with the most sunshine days is December (21.7 days).
The month with the least sunshine days is June (12.4 days).
Average UV index in December
Rockbridge, 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
Rockbridge, IL
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are August and September (Cloud cover 28).
Average visibility in December
Rockbridge, 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).
