December weather forecast
Fayetteville, IL

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Weather in December

December, the first month of the winter in Fayetteville, is also a frosty month, with an average temperature fluctuating between 31.1°F (-0.5°C) and 43.3°F (6.3°C).

Temperature

December ushers in a slight temperature change, with average high-temperatures reducing from November's fresh 53.6°F (12°C) to a frosty 43.3°F (6.3°C). December brings Fayetteville a consistent average low-temperature of 31.1°F (-0.5°C).

Humidity

In Fayetteville, Illinois, the average relative humidity in December is 77%.

Rainfall

In Fayetteville, in December, it is raining for 6.5 days, with typically 1.18" (30mm) of accumulated precipitation. Throughout the year, there are 129.8 rainfall days, and 19.13" (486mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through March, September through December. In December, it is snowing for 3.1 days. Throughout December, 0.55" (14mm) of snow is accumulated. In Fayetteville, during the entire year, snow falls for 16.2 days and aggregates up to 3.19" (81mm) of snow.

Daylight

December has the shortest days of the year in Fayetteville, with an average of 9h and 30min of daylight.
On the first day of the month, sunrise is at 6:58 am and sunset at 4:38 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:48 pm CST.

Sunshine

In December, the average sunshine is 4.9h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: The UV index of 2 during December leads to these advisories:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Updated: Jul 23, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

The high-temperature, in December, in Fayetteville, is 43.3°F (6.3°C), while the low-temperature averages to 31.1°F (-0.5°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, is appraised at 95°F (35°C).

What is the average humidity in December?

In December, the average relative humidity is 77%.

How much does it rain in December?

In Fayetteville, in December, during 6.5 rainfall days, 1.18" (30mm) of precipitation is typically accumulated.

How many days does it snow in December?

In Fayetteville, in December, snow falls for 3.1 days, with typically accumulated 0.55" (14mm) of snow.

What is the month with the shortest days?

With an average of 9h and 30min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

In December, the average day length is 9h and 32min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 6:58 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:48 pm CST.

How many hours of sunshine does Fayetteville have in December?

The average sunshine duration in December is 4.9h.

What are the months with the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

How high is the UV index in December in Fayetteville?

In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Fayetteville, IL

Average temperature in December - Fayetteville, IL
  • Average high temperature in December: 43.3°F

The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.3°F).

  • Average low temperature in December: 31.1°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).

Average pressure in December
Fayetteville, IL

Average pressure in December - Fayetteville, 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
Fayetteville, IL

Average wind speed in December - Fayetteville, IL
  • Average wind speed in December: 8.7mph

The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.6mph).

Average humidity in December
Fayetteville, IL

Average humidity in December - Fayetteville, IL
  • Average humidity in December: 77%

The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).

Average rainfall in December
Fayetteville, IL

Average rainfall in December - Fayetteville, IL
  • Average rainfall in December: 1.18"

The wettest month (with the highest rainfall) is May (2.48").
The driest month (with the least rainfall) is February (0.83").

Average rainfall days in December
Fayetteville, IL

Average rainfall days in December - Fayetteville, IL
  • Average rainfall days in December: 6.5 days

The month with the highest number of rainy days is July (15.1 days).
The months with the least rainy days are January and December (6.5 days).

Average snowfall in December
Fayetteville, IL

Average snowfall in December - Fayetteville, IL
  • Average snowfall in December: 0.55"

The month with the highest snowfall is January (1.06").
The months with the least snowfall are April, May, June, July and August (0").

Average snowfall days in December
Fayetteville, IL

Average snowfall days in December - Fayetteville, IL
  • Average snowfall days in December: 3.1 days

The month with the highest number of snowfall days is January (5.6 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Fayetteville, IL

Average daylight in December / Average sunshine in December - Fayetteville, 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 5min

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 42min).

Average sunshine days in December
Fayetteville, IL

Average sunshine days in December - Fayetteville, IL
  • Average sunshine days in December: 21.7 days

The month with the most sunshine days is December (21.7 days).
The month with the least sunshine days is July (13.7 days).

Average UV index in December
Fayetteville, IL

Average UV index in December - Fayetteville, 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
Fayetteville, IL

Average cloud cover in December - Fayetteville, IL
  • Average cloud cover in December: 47

The months with the most cloud cover are January and February (Cloud cover 49).
The months with the least cloud cover are June and August (Cloud cover 27).

Average visibility in December
Fayetteville, IL

Average visibility in December - Fayetteville, 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).

Fayetteville, Illinois, USA

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