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's arrival correlates with a reduction in the average high-temperature, down from a chilly 46°F (7.8°C) in November to a wintry 35.1°F (1.7°C). December notes an average low temperature of 26.6°F (-3°C) in Summit, Illinois, subtly down from the daytime highs.Humidity
In Summit, the average relative humidity in December is 79%.Rainfall
The month with the least rainfall is December, when the rain falls for 5.5 days and typically collects 0.43" (11mm) of precipitation.Snowfall
January through April, October through December are months with snowfall in Summit. In Summit, during December, snow falls for 6.5 days and regularly aggregates up to 0.31" (8mm) of snow. In Summit, during the entire year, snow falls for 32.3 days and aggregates up to 4.09" (104mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:59 am and sunset at 4:21 pm. On the last day of December, in Summit, sunrise is at 7:18 am and sunset at 4:30 pm CST.
Sunshine
The average sunshine in December is 4.1h.UV index
The month with the lowest UV index in Summit, Illinois, is December, with an average maximum UV index of 1. 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, a daily UV index of 1 turns into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Summit in December?
What is the average humidity in December in Summit?
What is the driest month in Summit?
How many days does it rain in December in Summit?
How many days does it snow in December in Summit?
What is the month with the shortest days in Summit?
What is the average length of the day in December in Summit?
When are sunrise and sunset in December in Summit?
How many hours of sunshine does Summit have in December?
What is the month with the lowest UV index in Summit?
How high is the UV index in December in Summit?
Average temperature in December
Summit, IL
- Average high temperature in December: 35.1°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (29.5°F).
- Average low temperature in December: 26.6°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).
Average pressure in December
Summit, 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
Summit, IL
- Average wind speed in December: 10.2mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in December
Summit, IL
- Average humidity in December: 79%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Summit, IL
- Average rainfall in December: 0.43"
The wettest month (with the highest rainfall) is May (1.38").
The driest month (with the least rainfall) is December (0.43").
Average rainfall days in December
Summit, IL
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is July (13.3 days).
The month with the least rainy days is February (4.1 days).
Average snowfall in December
Summit, IL
- Average snowfall in December: 0.31"
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Summit, IL
- Average snowfall days in December: 6.5 days
The month with the highest number of snowfall days is January (10.1 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
Summit, IL
- Average daylight in December: 9h and 1min
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: 4h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Summit, IL
- Average sunshine days in December: 21.2 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in December
Summit, 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
Summit, 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 27).
Average visibility in December
Summit, 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).
Summit, Illinois, USA
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