December weather forecast
Knoxville, IL

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Weather in December

The first month of the winter, December, is also an icy month in Knoxville, Illinois, with an average temperature varying between 24.6°F (-4.1°C) and 35.4°F (1.9°C).

Temperature

Onset of December witnesses a reduction in the average high-temperature, falling from a chilly 47.5°F (8.6°C) in November to a wintry 35.4°F (1.9°C). Knoxville experiences an average temperature drop to a subzero cold 24.6°F (-4.1°C) during December nights.

Humidity

The average relative humidity in December is 81%.

Rainfall

January and December are months with the least rain in Knoxville when the rain falls for 4.5 days and typically aggregates up to 0.47" (12mm) of rain.

Snowfall

January through April, October through December are months with snowfall. In Knoxville, during December, snow falls for 6 days and regularly aggregates up to 0.43" (11mm) of snow. Throughout the year, there are 28 snowfall days, and 4.53" (115mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 7:07 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:43 pm CST.

Sunshine

In December, the average sunshine is 4.4h.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: In December, an average UV index of 1 transforms into the following instructions:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.

Frequently asked questions

How cold is December in Knoxville?

December temperatures vary between a high-temperature of 35.4°F (1.9°C) and a low-temperature of 24.6°F (-4.1°C). The average heat index (a.k.a. 'feels like', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in August is estimated at 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December is 81%.

What is the driest month?

The months with the least rainfall are January and December Rain falls for 4.5 days and accumulates 0.47" (12mm) of rain.

How much does it rain in December?

In December, the rain falls for 4.5 days. Throughout December, 0.47" (12mm) of precipitation is accumulated.

How much does it snow in December?

In December, it is snowing for 6 days. Throughout December, 0.43" (11mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 18min of daylight.

What is the average length of the day in December?

The average day length in December is 9h and 17min.

What time are sunrise and sunset in December in Knoxville?

In December, on the first day of the month, sunrise is at 7:07 am and sunset at 4:33 pm. On the last day of the month, in Knoxville, Illinois, sunrise is at 7:25 am and sunset at 4:43 pm CST.

How long on average sun shines in December?

In December, the average sunshine duration is 4.4h.

When is the lowest UV index?

December is the month with the lowest UV index, with an average maximum UV index of 1.

How high is the UV index in December?

In December, the average daily maximum UV index is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation.
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
Knoxville, IL

Average temperature in December - Knoxville, IL
  • Average high temperature in December: 35.4°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.5°F).

  • Average low temperature in December: 24.6°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).

Average pressure in December
Knoxville, IL

Average pressure in December - Knoxville, IL
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
Knoxville, IL

Average wind speed in December - Knoxville, IL
  • Average wind speed in December: 9.9mph

The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity in December
Knoxville, IL

Average humidity in December - Knoxville, IL
  • Average humidity in December: 81%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Knoxville, IL

Average rainfall in December - Knoxville, IL
  • Average rainfall in December: 0.47"

The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are January and December (0.47").

Average rainfall days in December
Knoxville, IL

Average rainfall days in December - Knoxville, IL
  • Average rainfall days in December: 4.5 days

The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is February (3.9 days).

Average snowfall in December
Knoxville, IL

Average snowfall in December - Knoxville, IL
  • Average snowfall in December: 0.43"

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
Knoxville, IL

Average snowfall days in December - Knoxville, IL
  • Average snowfall days in December: 6 days

The month with the highest number of snowfall days is January (8.8 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
Knoxville, IL

Average daylight in December / Average sunshine in December - Knoxville, IL
  • Average daylight in December: 9h and 2min

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 18min).

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).

Average sunshine days in December
Knoxville, IL

Average sunshine days in December - Knoxville, IL
  • Average sunshine days in December: 21.6 days

The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (12.4 days).

Average UV index in December
Knoxville, IL

Average UV index in December - Knoxville, IL
  • Average UV index in December: 1

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Knoxville, IL

Average cloud cover in December - Knoxville, IL
  • Average cloud cover in December: 54

The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in December
Knoxville, IL

Average visibility in December - Knoxville, IL
  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).

Knoxville, Illinois, USA

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