December weather forecastIron, IL
December
Weather in December
The first month of the winter, December, is also a frosty month in Iron, Illinois, with an average temperature varying between 43.5°F (6.4°C) and 32.2°F (0.1°C).Temperature
December indicates a shift in the average high-temperature, from November's cool 53.6°F (12°C) to a chilly 43.5°F (6.4°C). Throughout the month of December, the nighttime temperature dips to an average of 32.2°F (0.1°C).Humidity
The average relative humidity in December is 78%.Rainfall
In December, the rain falls for 6.2 days. Throughout December, 0.59" (15mm) of precipitation is accumulated. Throughout the year, there are 100.2 rainfall days, and 8.7" (221mm) of precipitation is accumulated.Snowfall
Months with snowfall in Iron are January through March, November and December. In Iron, during December, snow falls for 1.9 days and regularly aggregates up to 0.12" (3mm) of snow. In Iron, Illinois, during the entire year, snow falls for 10.1 days and aggregates up to 0.91" (23mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 36min of daylight.On the first day of December, sunrise is at 6:50 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 4:43 pm CST.
Sunshine
In December, the average sunshine is 4.7h.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 unsafe exposure to UV radiation for the ordinary person.Note: In December, the maximum UV index of 2 suggests these recommendations:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. 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
Average temperature in December
Iron, IL
- Average high temperature in December: 43.5°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in December: 32.2°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in December
Iron, IL
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Iron, IL
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in December
Iron, IL
- Average humidity in December: 78%
The months with the highest relative humidity are May and July (79%).
The month with the lowest relative humidity is October (69%).
Average rainfall in December
Iron, IL
- Average rainfall in December: 0.59"
The wettest month (with the highest rainfall) is April (1.06").
The driest month (with the least rainfall) is September (0.28").
Average rainfall days in December
Iron, IL
- Average rainfall days in December: 6.2 days
The month with the highest number of rainy days is May (11.9 days).
The month with the least rainy days is January (5 days).
Average snowfall in December
Iron, IL
- Average snowfall in December: 0.12"
The months with the highest snowfall are January and February (0.28").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Iron, IL
- Average snowfall days in December: 1.9 days
The month with the highest number of snowfall days is January (3.3 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
Iron, IL
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 4h and 42min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Iron, IL
- Average sunshine days in December: 22.5 days
The month with the most sunshine days is October (23.4 days).
The month with the least sunshine days is May (15.8 days).
Average UV index in December
Iron, IL
- Average UV index in December: 2
The months with the highest UV index are May, 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
Iron, IL
- Average cloud cover in December: 50
The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 27).
Average visibility in December
Iron, 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).
