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 sea temperature 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 corresponds with a decrease in average high-temperatures, from November's frosty 46°F (7.8°C) to a cold 35.8°F (2.1°C). Chicago registers an average low-temperature of 27.9°F (-2.3°C) throughout December, a modest decrease from its daytime highs.Humidity
The average relative humidity in December is 80%.Rainfall
December is the month with the least rainfall. Rain falls for 8.8 days and accumulates 1.65" (42mm) of precipitation.Snowfall
January through May, November and December are months with snowfall. In December, it is snowing for 7.5 days. Throughout December, 2.52" (64mm) of snow is accumulated. In Chicago, during the entire year, snow falls for 40.9 days and aggregates up to 13.9" (353mm) of snow.Ocean temperature
In December, the average ocean temperature is 42.4°F (5.8°C).Note: With an efficient thermal swimsuit, one can navigate 42.4°F (5.8°C) even if it's colder than 50°F (10°C); otherwise, rapid cold shock and breathlessness might set in. Barely wading at 55.4°F (13°C) feels chilly.
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 6:59 am and sunset at 4:20 pm. On the last day of December, sunrise is at 7:18 am and sunset at 4:29 pm CST.
Sunshine
The average sunshine in December is 4h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: In December, the maximum UV index of 1 transforms into these recommendations:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather Atlas | 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 many days does it rain in December?
How much does it snow in December?
What is the water temperature in December?
What is the month with the shortest days?
How many hours of daylight does Chicago have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December in Chicago?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Chicago, IL
- Average high temperature in December: 35.8°F
The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in December: 27.9°F
The month with the highest average low temperature is July (67.8°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure in December
Chicago, 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
Chicago, IL
- Average wind speed in December: 11.7mph
The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest month (with the lowest average wind speed) is July (7.7mph).
Average humidity in December
Chicago, IL
- Average humidity in December: 80%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Chicago, IL
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is June (4.88").
The driest month (with the least rainfall) is December (1.65").
Average rainfall days in December
Chicago, IL
- Average rainfall days in December: 8.8 days
The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is February (5.5 days).
Average snowfall in December
Chicago, IL
- Average snowfall in December: 2.52"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Chicago, IL
- Average snowfall days in December: 7.5 days
The month with the highest number of snowfall days is January (10.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Chicago, IL
- Average sea temperature in December: 42.4°F
The best month for swimming (with the highest average sea temperature) is August (73.9°F).
The coldest month (with the lowest average sea temperature) is February (36.9°F).
Average daylight in December /
Average sunshine in December
Chicago, 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 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Chicago, IL
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is December (15.5 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in December
Chicago, IL
- Average UV index in December: 1
The months with the highest UV index are 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
Chicago, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in December
Chicago, 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).
Chicago, Illinois, USA
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