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 onset of December is marked by a decrease in temperature, transitioning from a frosty 46.6°F (8.1°C) in November to a wintry 34.7°F (1.5°C). Romeoville experiences a steady low-temperature of 24.6°F (-4.1°C) throughout December.Humidity
In Romeoville, the average relative humidity in December is 81%.Rainfall
The month with the least rainfall in Romeoville is December, when the rain falls for 7.1 days and typically collects 1.06" (27mm) of precipitation.Snowfall
January through May, October through December are months with snowfall in Romeoville. In Romeoville, in December, snow falls for 9.7 days, with typically accumulated 1.89" (48mm) of snow. Throughout the year, in Romeoville, there are 44.4 snowfall days, and 11.93" (303mm) of snow is accumulated.Daylight
December has the shortest days of the year in Romeoville, Illinois, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 7:00 am and sunset at 4:22 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:32 pm CST.
Sunshine
The average sunshine in December is 4.1h.UV index
The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 1 during December leads to these advisories:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Frequently asked questions
How cold is December in Romeoville?
What is the average humidity in December in Romeoville?
What is the driest month in Romeoville?
How many days does it rain in December in Romeoville?
How much does it snow in Romeoville in December?
What is the month with the shortest days in Romeoville?
How many hours of daylight does Romeoville have in December?
When is the sunrise / sunset in December in Romeoville?
How many hours of sunshine does Romeoville have in December?
When is the lowest UV index in Romeoville?
What is the UV index intensity in December in Romeoville?
Average temperature in December
Romeoville, IL
- Average high temperature in December: 34.7°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 24.6°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in December
Romeoville, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Romeoville, IL
- Average wind speed in December: 9mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Romeoville, 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 (73%).
Average rainfall in December
Romeoville, IL
- Average rainfall in December: 1.06"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is December (1.06").
Average rainfall days in December
Romeoville, IL
- Average rainfall days in December: 7.1 days
The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in December
Romeoville, IL
- Average snowfall in December: 1.89"
The month with the highest snowfall is January (3.11").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Romeoville, IL
- Average snowfall days in December: 9.7 days
The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Romeoville, 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 months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Romeoville, IL
- Average sunshine days in December: 16.2 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in December
Romeoville, 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
Romeoville, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Romeoville, IL
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Romeoville, Illinois, USA
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