December weather forecastCastle Junction, IL
December
Weather in December
The first month of the winter, December, is still a cold month in Castle Junction, Illinois, with an average temperature ranging between min 24.1°F (-4.4°C) and max 34.5°F (1.4°C).Temperature
Castle Junction's December weather features a mild decline in high-temperatures, reducing from a chilly 47.1°F (8.4°C) in November to a cold 34.5°F (1.4°C). In Castle Junction, an average nighttime temperature of 24.1°F (-4.4°C) is expected during December.Humidity
The average relative humidity in December in Castle Junction is 81%.Rainfall
December is the month with the least rainfall. Rain falls for 6.6 days and accumulates 0.75" (19mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Castle Junction, in December, snow falls for 7.8 days, with typically accumulated 1.42" (36mm) of snow. In Castle Junction, during the entire year, snow falls for 35.4 days and aggregates up to 8.35" (212mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:09 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 4:43 pm CST.
Sunshine
In Castle Junction, the average sunshine in December is 4.4h.UV index
The average daily maximum UV index in December in Castle Junction, Illinois, is 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: In December, an average UV index of 2 transforms into the following instructions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Castle Junction, IL
- Average high temperature in December: 34.5°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in December: 24.1°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in December
Castle Junction, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Castle Junction, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in December
Castle Junction, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Castle Junction, IL
- Average rainfall in December: 0.75"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is December (0.75").
Average rainfall days in December
Castle Junction, IL
- Average rainfall days in December: 6.6 days
The month with the highest number of rainy days is June (17 days).
The month with the least rainy days is January (4.2 days).
Average snowfall in December
Castle Junction, IL
- Average snowfall in December: 1.42"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Castle Junction, IL
- Average snowfall days in December: 7.8 days
The month with the highest number of snowfall days is January (10.3 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
Castle Junction, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in December
Castle Junction, IL
- Average sunshine days in December: 18.6 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in December
Castle Junction, IL
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Castle Junction, IL
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
Castle Junction, 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).
