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
Winnetka's December weather shows a moderate shift in high-temperatures, falling from November's chilly 45.5°F (7.5°C) to a cold 34.9°F (1.6°C). The temperature in Winnetka during December nights demonstrates a small drop from the daytime highs, settling to an average of 26.1°F (-3.3°C).Humidity
In Winnetka, the average relative humidity in December is 80%.Rainfall
The month with the least rainfall in Winnetka is December, when the rain falls for 9.1 days and typically collects 1.65" (42mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Winnetka, during December, snow falls for 10 days and regularly aggregates up to 2.99" (76mm) of snow. Throughout the year, there are 47.6 snowfall days, and 17.8" (452mm) 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 December, sunrise is at 7:00 am and sunset at 4:20 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:29 pm CST.
Sunshine
The average sunshine in December is 4h.UV index
The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 1 in December interprets into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. To guard against the harmful effects of the Sun, minimize exposure during midday. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in 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 month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
How many hours of sunshine does Winnetka have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Winnetka, IL
- Average high temperature in December: 34.9°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 26.1°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 (18.9°F).
Average pressure in December
Winnetka, 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
Winnetka, IL
- Average wind speed in December: 10.7mph
The windiest month (with the highest average wind speed) is January (11.5mph).
The calmest month (with the lowest average wind speed) is August (7.1mph).
Average humidity in December
Winnetka, 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
Winnetka, IL
- Average rainfall in December: 1.65"
The wettest months (with the highest rainfall) are May and June (4.57").
The driest month (with the least rainfall) is December (1.65").
Average rainfall days in December
Winnetka, IL
- Average rainfall days in December: 9.1 days
The month with the highest number of rainy days is May (19.1 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in December
Winnetka, IL
- Average snowfall in December: 2.99"
The month with the highest snowfall is January (4.84").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Winnetka, IL
- Average snowfall days in December: 10 days
The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Winnetka, 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 24min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Winnetka, IL
- Average sunshine days in December: 14.3 days
The month with the most sunshine days is November (15.5 days).
The month with the least sunshine days is June (9.2 days).
Average UV index in December
Winnetka, 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
Winnetka, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 28).
Average visibility in December
Winnetka, 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).
Winnetka, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location