December weather forecast
Saint Charles, IL

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Weather in December

The first month of the winter, December, is also an icy month in Saint Charles, Illinois, with temperature in the range of an average low of 23.5°F (-4.7°C) and an average high of 34.2°F (1.2°C).

Temperature

Setting in of December comes with a decrease in the average high-temperature, moving from a chilly 45.5°F (7.5°C) in November to a wintry 34.2°F (1.2°C). An average nighttime temperature of 23.5°F (-4.7°C) is noted during the month of December.

Humidity

In December, the average relative humidity in Saint Charles is 82%.

Rainfall

November and December are months with the least rain when the rain falls for 5 days and typically aggregates up to 0.39" (10mm) of rain.

Snowfall

Months with snowfall are January through April, October through December. In Saint Charles, in December, during 5.6 snowfall days, 0.35" (9mm) of snow is typically accumulated. In Saint Charles, during the entire year, snow falls for 28.3 days and aggregates up to 3.74" (95mm) 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 December, sunrise is at 7:02 am and sunset at 4:22 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:32 pm CST.

Sunshine

The average sunshine in December is 4.1h.

UV index

The months with the lowest UV index in Saint Charles are January and December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: In December, the maximum UV index of 1 translates into these guidelines:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Saint Charles in December?

The average high-temperature and low-temperature in Saint Charles, Illinois, during December are 34.2°F (1.2°C) and 23.5°F (-4.7°C) respectively. In July, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 86°F (30°C).

What is the average humidity in December in Saint Charles?

In December, the average relative humidity in Saint Charles is 82%.

What is the driest month in Saint Charles?

The months with the least rainfall in Saint Charles are November and December Rain falls for 5 days and accumulates 0.39" (10mm) of rain.

How much does it rain in Saint Charles in December?

In Saint Charles, in December, during 5 rainfall days, 0.39" (10mm) of precipitation is typically accumulated.

How much does it snow in Saint Charles in December?

In Saint Charles, in December, snow falls for 5.6 days, with typically accumulated 0.35" (9mm) of snow.

What is the month with the shortest days in Saint Charles?

December has the shortest days of the year in Saint Charles, Illinois, with an average of 9h and 12min of daylight.

What is the average length of the day in December in Saint Charles?

In December, the average day length is 9h and 11min.

What time are sunrise and sunset in December in Saint Charles?

In December, on the first day of the month, sunrise is at 7:02 am and sunset at 4:22 pm. On the last day of the month, in Saint Charles, Illinois, sunrise is at 7:20 am and sunset at 4:32 pm CST.

How many hours of sunshine does Saint Charles have in December?

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

What are the months with the lowest UV index in Saint Charles?

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

How high is the UV index in December in Saint Charles?

The average daily maximum UV index in December is 1. A UV Index 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
Saint Charles, IL

Average temperature in December - Saint Charles, IL
  • Average high temperature in December: 34.2°F

The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (27.9°F).

  • Average low temperature in December: 23.5°F

The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).

Average pressure in December
Saint Charles, IL

Average pressure in December - Saint Charles, IL
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Saint Charles, IL

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

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).

Average humidity in December
Saint Charles, IL

Average humidity in December - Saint Charles, IL
  • Average humidity in December: 82%

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).

Average rainfall in December
Saint Charles, IL

Average rainfall in December - Saint Charles, IL
  • Average rainfall in December: 0.39"

The wettest month (with the highest rainfall) is May (1.26").
The driest months (with the least rainfall) are November and December (0.39").

Average rainfall days in December
Saint Charles, IL

Average rainfall days in December - Saint Charles, IL
  • Average rainfall days in December: 5 days

The month with the highest number of rainy days is May (12.4 days).
The month with the least rainy days is January (3.4 days).

Average snowfall in December
Saint Charles, IL

Average snowfall in December - Saint Charles, IL
  • Average snowfall in December: 0.35"

The month with the highest snowfall is January (1.14").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Saint Charles, IL

Average snowfall days in December - Saint Charles, IL
  • Average snowfall days in December: 5.6 days

The month with the highest number of snowfall days is January (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Saint Charles, IL

Average daylight in December / Average sunshine in December - Saint Charles, IL
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 12min).
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 July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in December
Saint Charles, IL

Average sunshine days in December - Saint Charles, IL
  • Average sunshine days in December: 22.4 days

The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is June (13.3 days).

Average UV index in December
Saint Charles, IL

Average UV index in December - Saint Charles, IL
  • Average UV index in December: 1

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

Average cloud cover in December
Saint Charles, IL

Average cloud cover in December - Saint Charles, IL
  • Average cloud cover in December: 59

The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is September (Cloud cover 32).

Average visibility in December
Saint Charles, IL

Average visibility in December - Saint Charles, 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).

Saint Charles, Illinois, USA

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