December weather forecastRiverwoods, IL
December
Weather in December
December, the first month of the winter in Riverwoods, is still a cold month, with an average temperature fluctuating between 25.5°F (-3.6°C) and 34.5°F (1.4°C).Temperature
The start of December comes with a reduction in the average high-temperature, receding from a frosty 45.3°F (7.4°C) in November to a cold 34.5°F (1.4°C). Riverwoods's December nights witness minimal differential from the daytime temperatures, with averages of 25.5°F (-3.6°C).Humidity
In December, the average relative humidity in Riverwoods is 80%.Rainfall
In Riverwoods, during December, the rain falls for 9.5 days and regularly aggregates up to 1.65" (42mm) of precipitation. Throughout the year, there are 143.1 rainfall days, and 26.97" (685mm) of precipitation is accumulated.Snowfall
Months with snowfall in Riverwoods are January through May, October through December. In Riverwoods, Illinois, during December, snow falls for 10.2 days and regularly aggregates up to 2.95" (75mm) of snow. In Riverwoods, Illinois, during the entire year, snow falls for 48.6 days and aggregates up to 18.78" (477mm) 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 7:01 am and sunset at 4:20 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:29 pm CST.
Sunshine
The average sunshine in December in Riverwoods is 4h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the average person.Note: An average UV index of 1 in December transforms into this advice:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Riverwoods, IL
- Average high temperature in December: 34.5°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (28.6°F).
- Average low temperature in December: 25.5°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).
Average pressure in December
Riverwoods, IL
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Riverwoods, IL
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in December
Riverwoods, IL
- Average humidity in December: 80%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Riverwoods, IL
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is November (1.5").
Average rainfall days in December
Riverwoods, IL
- Average rainfall days in December: 9.5 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is February (6.3 days).
Average snowfall in December
Riverwoods, IL
- Average snowfall in December: 2.95"
The months with the highest snowfall are January and February (5.24").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Riverwoods, IL
- Average snowfall days in December: 10.2 days
The month with the highest number of snowfall days is January (13.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Riverwoods, IL
- Average daylight in December: 9h and 12min
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 0min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Riverwoods, IL
- Average sunshine days in December: 14 days
The month with the most sunshine days is October (17.3 days).
The month with the least sunshine days is February (10.4 days).
Average UV index in December
Riverwoods, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Riverwoods, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Riverwoods, 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).
