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
As December begins, there is a decrease in the average high-temperature, falling from a chilly 45.1°F (7.3°C) in November to a cold 33.4°F (0.8°C). The nighttime temperature, during December, averages of 23.4°F (-4.8°C).Humidity
The average relative humidity in December is 82%.Rainfall
The month with the least rainfall is December, when the rain falls for 8.1 days and typically collects 1.1" (28mm) of precipitation.Snowfall
Months with snowfall in Sleepy Hollow, Illinois, are January through May, October through December. In Sleepy Hollow, in December, during 10.5 snowfall days, 2.2" (56mm) of snow is typically accumulated. In Sleepy Hollow, during the entire year, snow falls for 47.4 days and aggregates up to 13.07" (332mm) of snow.Daylight
The month with the shortest days in Sleepy Hollow is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:02 am and sunset at 4:22 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:31 pm CST.
Sunshine
In December, the average sunshine is 3.9h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index in Sleepy Hollow. A UV Index estimate of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum daily UV index of 1 in December converts into the following recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December in Sleepy Hollow?
What is the average humidity in December in Sleepy Hollow?
What is the driest month in Sleepy Hollow?
How many days does it rain in December in Sleepy Hollow?
How much does it snow in Sleepy Hollow in December?
What is the month with the shortest days in Sleepy Hollow?
How many hours of daylight does Sleepy Hollow have in December?
What time are sunrise and sunset in December in Sleepy Hollow?
How many hours of sunshine does Sleepy Hollow have in December?
What are the months with the lowest UV index in Sleepy Hollow?
What is the UV index intensity in December in Sleepy Hollow?
Average temperature in December
Sleepy Hollow, IL
- Average high temperature in December: 33.4°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in December: 23.4°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (15.4°F).
Average pressure in December
Sleepy Hollow, 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
Sleepy Hollow, IL
- Average wind speed in December: 9.3mph
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
Sleepy Hollow, IL
- Average humidity in December: 82%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (75%).
Average rainfall in December
Sleepy Hollow, IL
- Average rainfall in December: 1.1"
The wettest month (with the highest rainfall) is June (3.03").
The driest month (with the least rainfall) is December (1.1").
Average rainfall days in December
Sleepy Hollow, IL
- Average rainfall days in December: 8.1 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in December
Sleepy Hollow, IL
- Average snowfall in December: 2.2"
The month with the highest snowfall is January (3.62").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Sleepy Hollow, IL
- Average snowfall days in December: 10.5 days
The month with the highest number of snowfall days is January (12.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Sleepy Hollow, 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: 3h and 5min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Sleepy Hollow, IL
- Average sunshine days in December: 14.6 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (10.1 days).
Average UV index in December
Sleepy Hollow, 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
Sleepy Hollow, 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 August and September (Cloud cover 33).
Average visibility in December
Sleepy Hollow, IL
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
Sleepy Hollow, Illinois, USA
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