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
December comes with a drop in the average high-temperature, falling from November's frosty 46.9°F (8.3°C) to an icy 35.6°F (2°C). An average nighttime temperature of 25.9°F (-3.4°C) is witnessed throughout December.Humidity
The average relative humidity in December is 81%.Rainfall
The month with the least rainfall is December, when the rain falls for 7.9 days and typically collects 1.54" (39mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In December, it is snowing for 9.1 days. Throughout December, 2.76" (70mm) of snow is accumulated. In Thornton, Illinois, during the entire year, snow falls for 44.6 days and aggregates up to 16.46" (418mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 6:58 am and sunset at 4:21 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:30 pm CST.
Sunshine
In Thornton, the average sunshine in December is 4h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the average person.Note: In December, a regular UV index of 1 translates into these guidelines:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
What is the driest month?
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?
What time are sunrise and sunset in December?
How many hours of sunshine does Thornton have in December?
What is the month with the lowest UV index?
How high is the UV index in December in Thornton?
Average temperature in December
Thornton, IL
- Average high temperature in December: 35.6°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 (29.7°F).
- Average low temperature in December: 25.9°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Thornton, 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
Thornton, IL
- Average wind speed in December: 9.5mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in December
Thornton, IL
- Average humidity in December: 81%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Thornton, IL
- Average rainfall in December: 1.54"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").
Average rainfall days in December
Thornton, IL
- Average rainfall days in December: 7.9 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in December
Thornton, IL
- Average snowfall in December: 2.76"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Thornton, IL
- Average snowfall days in December: 9.1 days
The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Thornton, 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 0min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Thornton, IL
- Average sunshine days in December: 15 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).
Average UV index in December
Thornton, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Thornton, IL
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Thornton, 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).
Thornton, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location