December weather forecastRockton, IL
December
Weather in December
December, the first month of the winter in Rockton, is also a wintry month, with temperature in the range of an average high of 32.4°F (0.2°C) and an average low of 21.7°F (-5.7°C).Temperature
As December begins, there is a decrease in the average high-temperature, falling from a frosty 43.7°F (6.5°C) in November to an icy 32.4°F (0.2°C). Rockton observes an average nighttime temperature of 21.7°F (-5.7°C) during December.Humidity
In Rockton, Illinois, the average relative humidity in December is 83%.Rainfall
February and December are months with the least rain in Rockton, Illinois, when the rain falls for 5.5 days and typically aggregates up to 0.67" (17mm) of rain.Snowfall
January through April, October through December are months with snowfall in Rockton. In December, it is snowing for 8.5 days. Throughout December, 1.1" (28mm) of snow is accumulated. In Rockton, during the entire year, snow falls for 41.2 days and aggregates up to 8.78" (223mm) of snow.Daylight
December has the shortest days of the year in Rockton, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:06 am and sunset at 4:24 pm. On the last day of December, in Rockton, sunrise is at 7:25 am and sunset at 4:33 pm CST.
Sunshine
In December, the average sunshine is 3.8h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: In December, a regular UV index of 1 translates into these guidelines:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. To protect against the Sun's most potent rays, avoid direct exposure around midday. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. 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
Average temperature in December
Rockton, IL
- Average high temperature in December: 32.4°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (25.2°F).
- Average low temperature in December: 21.7°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (12.7°F).
Average pressure in December
Rockton, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Rockton, IL
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in December
Rockton, IL
- Average humidity in December: 83%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and October (76%).
Average rainfall in December
Rockton, IL
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is June (2.28").
The driest months (with the least rainfall) are February and December (0.67").
Average rainfall days in December
Rockton, IL
- Average rainfall days in December: 5.5 days
The months with the highest number of rainy days are May and June (15.3 days).
The month with the least rainy days is January (3.1 days).
Average snowfall in December
Rockton, IL
- Average snowfall in December: 1.1"
The month with the highest snowfall is January (2.52").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rockton, IL
- Average snowfall days in December: 8.5 days
The month with the highest number of snowfall days is January (11.5 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
Rockton, IL
- Average daylight in December: 9h and 6min
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 6min).
- Average sunshine in December: 3h and 48min
The months with the most sunshine are July and August (Average sunshine: 9h and 30min).
The months with the least sunshine are January and February (Average sunshine: 3h and 30min).
Average sunshine days in December
Rockton, IL
- Average sunshine days in December: 17.8 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in December
Rockton, IL
- Average UV index in December: 1
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Rockton, IL
- Average cloud cover in December: 61
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is September (Cloud cover 35).
Average visibility in December
Rockton, 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).
