December weather forecastBartlett, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Bartlett, Illinois, with an average temperature fluctuating between 34°F (1.1°C) and 23.9°F (-4.5°C).Temperature
The beginning of December marks a decrease in the average high-temperature, transitioning from a chilly 45.5°F (7.5°C) in November to a cold 34°F (1.1°C). During December, the temperature is averaged to a low of 23.9°F (-4.5°C) at night.Humidity
In December, the average relative humidity is 81%.Rainfall
The month with the least rainfall is December, when the rain falls for 7.2 days and typically collects 1.02" (26mm) of precipitation.Snowfall
Months with snowfall in Bartlett are January through May, October through December. In Bartlett, during December, snow falls for 10.6 days and regularly aggregates up to 2.13" (54mm) of snow. Throughout the year, there are 46.4 snowfall days, and 13.03" (331mm) of snow is accumulated.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 7:01 am and sunset at 4:22 pm. On the last day of December, sunrise is at 7:20 am and sunset at 4:31 pm CST.
Sunshine
The average sunshine in December is 3.9h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the average maximum UV index of 1 translates into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. It's recommended to limit sun exposure when its radiation is at its peak during midday. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Bartlett, IL
- Average high temperature in December: 34°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 (27.7°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.3°F).
Average pressure in December
Bartlett, IL
- Average pressure in December: 30.09"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
Bartlett, IL
- Average wind speed in December: 9.2mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in December
Bartlett, 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 (74%).
Average rainfall in December
Bartlett, IL
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is December (1.02").
Average rainfall days in December
Bartlett, IL
- Average rainfall days in December: 7.2 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is February (4.8 days).
Average snowfall in December
Bartlett, IL
- Average snowfall in December: 2.13"
The month with the highest snowfall is January (3.39").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Bartlett, IL
- Average snowfall days in December: 10.6 days
The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Bartlett, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 3h and 54min
The months with the most sunshine are July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Bartlett, IL
- Average sunshine days in December: 15.6 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is July (10.9 days).
Average UV index in December
Bartlett, IL
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Bartlett, IL
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July, August and September (Cloud cover 33).
Average visibility in December
Bartlett, 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).
