Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
With December's arrival, Royalton, Illinois, sees a decrease in average high-temperatures, moving from a cool 54°F (12.2°C) in November to a chilly 43.7°F (6.5°C). Throughout December, the average low-temperature records at a freezing cold 31.8°F (-0.1°C).Humidity
In Royalton, the average relative humidity in December is 77%.Rainfall
In Royalton, during December, the rain falls for 10.3 days and regularly aggregates up to 2.2" (56mm) of precipitation. Throughout the year, there are 158.6 rainfall days, and 34.69" (881mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall in Royalton. In Royalton, Illinois, during December, snow falls for 3 days and regularly aggregates up to 1.26" (32mm) of snow. Throughout the year, there are 15.9 snowfall days, and 5.71" (145mm) of snow is accumulated.Daylight
December has the shortest days of the year in Royalton, Illinois, with an average of 9h and 36min of daylight.On the first day of the month, sunrise is at 6:53 am and sunset at 4:37 pm. On the last day of December, in Royalton, sunrise is at 7:12 am and sunset at 4:47 pm CST.
Sunshine
In Royalton, the average sunshine in December is 4.8h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 2 in December translates into these instructions:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. 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. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in Royalton?
What is the average humidity in December in Royalton?
How many days does it rain in December in Royalton?
How much does it snow in Royalton in December?
What is the month with the shortest days in Royalton?
What is the average length of the day in December in Royalton?
When is the sunrise / sunset in December in Royalton?
How many hours of sunshine does Royalton have in December?
What is the month with the lowest UV index in Royalton?
How high is the UV index in December in Royalton?
Average temperature in December
Royalton, IL
- Average high temperature in December: 43.7°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.6°F).
- Average low temperature in December: 31.8°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in December
Royalton, 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 (29.93"Hg).
Average wind speed in December
Royalton, IL
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in December
Royalton, IL
- Average humidity in December: 77%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Royalton, IL
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is April (4.49").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Royalton, IL
- Average rainfall days in December: 10.3 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in December
Royalton, IL
- Average snowfall in December: 1.26"
The month with the highest snowfall is February (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Royalton, IL
- Average snowfall days in December: 3 days
The months with the highest number of snowfall days are January and February (4.8 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
Royalton, IL
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 4h and 5min
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 42min).
Average sunshine days in December
Royalton, IL
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is October (18.5 days).
The month with the least sunshine days is May (11.3 days).
Average UV index in December
Royalton, 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
Royalton, IL
- Average cloud cover in December: 48
The month with the most cloud cover is February (Cloud cover 50).
The months with the least cloud cover are June and August (Cloud cover 27).
Average visibility in December
Royalton, 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).
Royalton, Illinois, USA
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