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
The move into December indicates a reduction in the average high-temperature, down from November's frosty 47.1°F (8.4°C) to a wintry 35.1°F (1.7°C). Throughout the month of December, Rockdale witnesses an average temperature of 25°F (-3.9°C).Humidity
In December, the average relative humidity is 82%.Rainfall
In Rockdale, during December, the rain falls for 8.1 days and regularly aggregates up to 1.69" (43mm) of precipitation. Throughout the year, in Rockdale, there are 153.6 rainfall days, and 32.72" (831mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Rockdale, in December, snow falls for 8 days, with typically accumulated 2.4" (61mm) of snow. In Rockdale, during the entire year, snow falls for 38.2 days and aggregates up to 14.61" (371mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:23 pm. On the last day of December, in Rockdale, sunrise is at 7:18 am and sunset at 4:32 pm CST.
Sunshine
In Rockdale, the average sunshine in December is 4.1h.UV index
The months with the lowest UV index in Rockdale are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for average individuals.Note: A typical high UV index of 1 in December suggests the following recommendations:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Frequently asked questions
How cold is it in Rockdale in December?
What is the average humidity in December in Rockdale?
How much does it rain in Rockdale in December?
How many days does it snow in December in Rockdale?
What is the month with the shortest days in Rockdale?
How many hours of daylight does Rockdale have in December?
When are sunrise and sunset in December in Rockdale?
How many hours of sunshine does Rockdale have in December?
When is the lowest UV index in Rockdale?
What is the UV index reading in December in Rockdale?
Average temperature in December
Rockdale, IL
- Average high temperature in December: 35.1°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in December: 25°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in December
Rockdale, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Rockdale, IL
- Average wind speed in December: 8.9mph
The windiest month (with the highest average wind speed) is April (9.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in December
Rockdale, IL
- Average humidity in December: 82%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Rockdale, IL
- Average rainfall in December: 1.69"
The wettest month (with the highest rainfall) is May (4.41").
The driest month (with the least rainfall) is February (1.61").
Average rainfall days in December
Rockdale, IL
- Average rainfall days in December: 8.1 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in December
Rockdale, IL
- Average snowfall in December: 2.4"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Rockdale, IL
- Average snowfall days in December: 8 days
The month with the highest number of snowfall days is January (11.9 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
Rockdale, IL
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 1min
The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Rockdale, IL
- Average sunshine days in December: 15.9 days
The month with the most sunshine days is November (18.1 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in December
Rockdale, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Rockdale, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).
Average visibility in December
Rockdale, IL
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
Rockdale, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location
