December weather forecast
Somonauk, IL

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Weather in December

The first month of the winter, December, is also a wintry month in Somonauk, Illinois, with an average temperature ranging between max 34.2°F (1.2°C) and min 23.9°F (-4.5°C).

Temperature

Somonauk's December weather comes with a decrease in average high-temperatures, moving from a chilly 45.5°F (7.5°C) in November to an icy 34.2°F (1.2°C). December brings with it a nighttime average temperature of 23.9°F (-4.5°C) in Somonauk.

Humidity

The average relative humidity in December is 82%.

Rainfall

In December, the rain falls for 8 days. Throughout December, 1.77" (45mm) of precipitation is accumulated. In Somonauk, during the entire year, the rain falls for 162.1 days and collects up to 33.54" (852mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In Somonauk, during December, snow falls for 8.9 days and regularly aggregates up to 2.6" (66mm) of snow. In Somonauk, during the entire year, snow falls for 43.6 days and aggregates up to 16.73" (425mm) of snow.

Daylight

December has the shortest days of the year, 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 4:25 pm. On the last day of December, sunrise is at 7:21 am and sunset at 4:34 pm CST.

Sunshine

In December, the average sunshine is 4.1h.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In December, the maximum UV index of 1 suggests this advice:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.

Frequently asked questions

How cold is December?

An average high-temperature, in December, in Somonauk, is 34.2°F (1.2°C) and the average low-temperature is 23.9°F (-4.5°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in July is computed to be 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December is 82%.

How many days does it rain in December?

In Somonauk, during December, the rain falls for 8 days and regularly aggregates up to 1.77" (45mm) of precipitation.

How much does it snow in December?

In December, it is snowing for 8.9 days. Throughout December, 2.6" (66mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 12min of daylight, December has the shortest days of the year in Somonauk.

How many hours of daylight does Somonauk have in December?

In December, the average day length is 9h and 13min.

When is the sunrise / sunset in December?

On the first day of December in Somonauk, sunrise is at 7:02 am and sunset at 4:25 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:34 pm CST.

How many hours of sunshine does Somonauk have in December?

In Somonauk, the average sunshine duration in December is 4.1h.

When is the lowest UV index?

January and December, with an average maximum UV index of 1, are months with the lowest UV index in Somonauk.

What is the UV index intensity in December?

In Somonauk, the average daily maximum UV index in December is 1. A UV Index value of 2, and less, symbolizes a low health threat 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
Somonauk, IL

Average temperature in December - Somonauk, IL
  • Average high temperature in December: 34.2°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 (27.5°F).

  • Average low temperature in December: 23.9°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).

Average pressure in December
Somonauk, IL

Average pressure in December - Somonauk, 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
Somonauk, IL

Average wind speed in December - Somonauk, IL
  • Average wind speed in December: 9.2mph

The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in December
Somonauk, IL

Average humidity in December - Somonauk, 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 (74%).

Average rainfall in December
Somonauk, IL

Average rainfall in December - Somonauk, IL
  • Average rainfall in December: 1.77"

The wettest month (with the highest rainfall) is May (4.49").
The driest month (with the least rainfall) is January (1.69").

Average rainfall days in December
Somonauk, IL

Average rainfall days in December - Somonauk, IL
  • Average rainfall days in December: 8 days

The months with the highest number of rainy days are June and July (19.3 days).
The month with the least rainy days is January (5.5 days).

Average snowfall in December
Somonauk, IL

Average snowfall in December - Somonauk, IL
  • Average snowfall in December: 2.6"

The month with the highest snowfall is January (4.61").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Somonauk, IL

Average snowfall days in December - Somonauk, IL
  • Average snowfall days in December: 8.9 days

The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Somonauk, 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 months with the most sunshine are June, July and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in December
Somonauk, IL

Average sunshine days in December - Somonauk, IL
  • Average sunshine days in December: 15.6 days

The month with the most sunshine days is November (17 days).
The month with the least sunshine days is July (8.2 days).

Average UV index in December
Somonauk, IL

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

The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in December
Somonauk, IL

Average cloud cover in December - Somonauk, IL
  • Average cloud cover in December: 57

The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).

Average visibility in December
Somonauk, IL

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

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

Somonauk, Illinois, USA

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