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
In Westchester, the average high-temperature in December drops from a chilly 45.9°F (7.7°C) in November to an icy 34.7°F (1.5°C). In December, the average low-temperature is a subzero cold 25.2°F (-3.8°C).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 1.14" (29mm) of precipitation.Snowfall
January through May, October through December are months with snowfall in Westchester. In Westchester, in December, during 9.9 snowfall days, 2.24" (57mm) of snow is typically accumulated. In Westchester, during the entire year, snow falls for 45.8 days and aggregates up to 14.25" (362mm) 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 December, sunrise is at 7:00 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:30 pm CST.
Sunshine
In Westchester, the average sunshine in December is 4.1h.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 low health risk from exposure to the Sun's UV rays for average individuals.Note: In December, the maximum UV index of 1 suggests these recommendations:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
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 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 in Westchester?
What time are sunrise and sunset in December?
How long on average sun shines in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Westchester, IL
- Average high temperature in December: 34.7°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 25.2°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in December
Westchester, 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
Westchester, IL
- Average wind speed in December: 9.4mph
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
Westchester, 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 (72%).
Average rainfall in December
Westchester, IL
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is December (1.14").
Average rainfall days in December
Westchester, IL
- Average rainfall days in December: 7.9 days
The months with the highest number of rainy days are May and July (17.3 days).
The month with the least rainy days is February (5.1 days).
Average snowfall in December
Westchester, IL
- Average snowfall in December: 2.24"
The month with the highest snowfall is February (3.86").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Westchester, IL
- Average snowfall days in December: 9.9 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Westchester, 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 months with the most sunshine are July and August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Westchester, IL
- Average sunshine days in December: 15.3 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is July (9.5 days).
Average UV index in December
Westchester, 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
Westchester, IL
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Westchester, 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).
Westchester, Illinois, USA
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