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 commences, the average high-temperature shows a reduction, transitioning from a cool 52°F (11.1°C) in November to an icy 41.5°F (5.3°C). Olney experiences a nighttime temperature average of 30.9°F (-0.6°C) during December.Humidity
In Olney, the average relative humidity in December is 78%.Rainfall
In December, the rain falls for 10.5 days. Throughout December, 2.17" (55mm) of precipitation is accumulated. Throughout the year, there are 152.3 rainfall days, and 27.99" (711mm) of precipitation is accumulated.Snowfall
Months with snowfall in Olney, Illinois, are January through April, November and December. In Olney, in December, snow falls for 4.5 days, with typically accumulated 1.34" (34mm) of snow. Throughout the year, in Olney, Illinois, there are 20.3 snowfall days, and 5.47" (139mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 6:52 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 4:41 pm CST.
Sunshine
In December, the average sunshine in Olney is 4.6h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in Olney?
What is the average humidity in December in Olney?
How many days does it rain in December in Olney?
How much does it snow in Olney in December?
What is the month with the shortest days in Olney?
How many hours of daylight does Olney have in December?
What time are sunrise and sunset in December in Olney?
How long on average sun shines in December in Olney?
What are the months with the lowest UV index in Olney?
What is the UV index reading in December in Olney?
Average temperature in December
Olney, IL
- Average high temperature in December: 41.5°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 30.9°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Olney, IL
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Olney, IL
- Average wind speed in December: 9.4mph
The windiest months (with the highest average wind speed) are January and February (10.2mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).
Average humidity in December
Olney, IL
- Average humidity in December: 78%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Olney, IL
- Average rainfall in December: 2.17"
The wettest month (with the highest rainfall) is April (4.09").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in December
Olney, IL
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (8.8 days).
Average snowfall in December
Olney, IL
- Average snowfall in December: 1.34"
The month with the highest snowfall is January (1.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Olney, IL
- Average snowfall days in December: 4.5 days
The month with the highest number of snowfall days is January (5.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Olney, IL
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Olney, IL
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is October (18.8 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in December
Olney, IL
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Olney, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in December
Olney, 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).
Olney, Illinois, USA
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