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
The onset of December introduces a moderate change in Leland's weather, with average high-temperatures falling from November's frosty 46.4°F (8°C) to a cold 34.5°F (1.4°C). December nights experience a consistent temperature drop to a freezing cold 24.3°F (-4.3°C).Humidity
In Leland, the average relative humidity in December is 82%.Rainfall
In Leland, during December, the rain falls for 5 days and regularly aggregates up to 0.51" (13mm) of precipitation. Throughout the year, there are 109.6 rainfall days, and 10.31" (262mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Leland, in December, during 5.9 snowfall days, 0.51" (13mm) of snow is typically accumulated. Throughout the year, in Leland, Illinois, there are 28.6 snowfall days, and 4.33" (110mm) of snow is accumulated.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 7:03 am and sunset at 4:25 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:35 pm CST.
Sunshine
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 in Leland. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index, 1 in December, converts into the following recommendations:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
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?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Leland have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Leland, IL
- Average high temperature in December: 34.5°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 (28.8°F).
- Average low temperature in December: 24.3°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (16.7°F).
Average pressure in December
Leland, IL
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Leland, IL
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in December
Leland, IL
- Average humidity in December: 82%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Leland, IL
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is May (1.54").
The driest month (with the least rainfall) is February (0.47").
Average rainfall days in December
Leland, IL
- Average rainfall days in December: 5 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in December
Leland, IL
- Average snowfall in December: 0.51"
The month with the highest snowfall is January (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Leland, IL
- Average snowfall days in December: 5.9 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Leland, IL
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
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 June (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in December
Leland, IL
- Average sunshine days in December: 21.3 days
The months with the most sunshine days are January and December (21.3 days).
The month with the least sunshine days is May (14.2 days).
Average UV index in December
Leland, IL
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Leland, IL
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 33).
Average visibility in December
Leland, IL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Leland, Illinois, USA
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