December weather forecastRound Lake Beach, IL
December
Weather in December
The first month of the winter, December, is still a cold month in Round Lake Beach, Illinois, with an average temperature ranging between min 23.9°F (-4.5°C) and max 33.6°F (0.9°C).Temperature
As Round Lake Beach, Illinois, enters December, the average high-temperature decreases from the a chilly 45.1°F (7.3°C) of November to a wintry 33.6°F (0.9°C). Round Lake Beach's average low-temperature is measured at a subzero cold 23.9°F (-4.5°C) during December.Humidity
The average relative humidity in December is 81%.Rainfall
The month with the least rainfall is December, when the rain falls for 8.2 days and typically collects 0.98" (25mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Round Lake Beach, during December, snow falls for 10.4 days and regularly aggregates up to 2.17" (55mm) of snow. Throughout the year, there are 49.5 snowfall days, and 13.54" (344mm) of snow is accumulated.Daylight
December has the shortest days of the year in Round Lake Beach, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:02 am and sunset at 4:20 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:29 pm CST.
Sunshine
In Round Lake Beach, the average sunshine in December is 4h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 1 in December translates into these instructions:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Round Lake Beach, IL
- Average high temperature in December: 33.6°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 (27.5°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in December
Round Lake Beach, IL
- Average pressure in December: 30.09"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Round Lake Beach, IL
- Average wind speed in December: 9.6mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in December
Round Lake Beach, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Round Lake Beach, IL
- Average rainfall in December: 0.98"
The wettest month (with the highest rainfall) is April (2.72").
The driest month (with the least rainfall) is December (0.98").
Average rainfall days in December
Round Lake Beach, IL
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is February (5 days).
Average snowfall in December
Round Lake Beach, IL
- Average snowfall in December: 2.17"
The month with the highest snowfall is January (3.58").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Round Lake Beach, IL
- Average snowfall days in December: 10.4 days
The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Round Lake Beach, 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: 4h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Round Lake Beach, IL
- Average sunshine days in December: 15.4 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in December
Round Lake Beach, IL
- Average UV index in December: 1
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Round Lake Beach, IL
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 30).
Average visibility in December
Round Lake Beach, IL
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





