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
In December, the meteorological conditions alter, with the average high-temperature shifting from a cool 54°F (12.2°C) in November to a frosty 43.9°F (6.6°C). An average low-temperature of 31.3°F (-0.4°C) is expected in Rockwood, Illinois, during December.Humidity
In Rockwood, the average relative humidity in December is 77%.Rainfall
In Rockwood, during December, the rain falls for 6.5 days and regularly aggregates up to 0.63" (16mm) of precipitation. In Rockwood, during the entire year, the rain falls for 111.9 days and collects up to 10.43" (265mm) of precipitation.Snowfall
Months with snowfall are January through March, October through December. In Rockwood, in December, during 1.8 snowfall days, 0.2" (5mm) of snow is typically accumulated. Throughout the year, there are 10.9 snowfall days, and 1.42" (36mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 36min of daylight.On the first day of the month, sunrise is at 6:56 am and sunset at 4:40 pm. On the last day of December, sunrise is at 7:14 am and sunset at 4:50 pm CST.
Sunshine
In December, the average sunshine is 5h.UV index
January, February and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the average person.Note: In December, the maximum UV index of 2 suggests these recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. When the Sun is at its strongest around midday, find shade and limit exposure. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold does it get in December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Rockwood have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Rockwood, IL
- Average high temperature in December: 43.9°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.4°F).
- Average low temperature in December: 31.3°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in December
Rockwood, 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
Rockwood, IL
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Rockwood, 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
Rockwood, IL
- Average rainfall in December: 0.63"
The wettest months (with the highest rainfall) are April and May (1.22").
The driest month (with the least rainfall) is September (0.43").
Average rainfall days in December
Rockwood, IL
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is July (13.4 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in December
Rockwood, IL
- Average snowfall in December: 0.2"
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in December
Rockwood, IL
- Average snowfall days in December: 1.8 days
The month with the highest number of snowfall days is January (3.7 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
Rockwood, 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: 5h and 0min
The months with the most sunshine are June and July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 48min).
Average sunshine days in December
Rockwood, IL
- Average sunshine days in December: 21.5 days
The month with the most sunshine days is October (21.9 days).
The month with the least sunshine days is July (13.5 days).
Average UV index in December
Rockwood, 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 and December (UV index 2).
Average cloud cover in December
Rockwood, IL
- Average cloud cover in December: 47
The months with the most cloud cover are January and February (Cloud cover 48).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in December
Rockwood, 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).
Rockwood, Illinois, USA
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