December weather forecast
Forest Park, IL

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Weather in December

The first month of the winter, December, is still a cold month in Forest Park, Illinois, with an average temperature fluctuating between 26.6°F (-3°C) and 35.1°F (1.7°C).

Temperature

As November transitions into December, Forest Park sees a drop in the average high-temperature, transitioning from a chilly 45.9°F (7.7°C) to an icy 35.1°F (1.7°C). In Forest Park, the average low-temperature during December nights tends to settle at a subzero cold 26.6°F (-3°C), indicating a slight drop from the daytime peak.

Humidity

In Forest Park, the average relative humidity in December is 80%.

Rainfall

The month with the least rainfall is December, when the rain falls for 8.2 days and typically collects 1.57" (40mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Forest Park, in December, during 8.3 snowfall days, 2.52" (64mm) of snow is typically accumulated. In Forest Park, during the entire year, snow falls for 40.3 days and aggregates up to 16.81" (427mm) of snow.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year in Forest Park.
On the first day of December, sunrise is at 7:00 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:30 pm CST.

Sunshine

The average sunshine in December in Forest Park is 4.1h.

UV index

The months with the lowest UV index 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 radiation for the ordinary person.
Note: A maximum UV index of 1 in December translates into the following recommendations:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Forest Park?

In December, in Forest Park, the average high-temperature is 35.1°F (1.7°C), and the average low-temperature is 26.6°F (-3°C).

What is the average humidity in December?

In Forest Park, the average relative humidity in December is 80%.

What is the driest month?

December is the month with the least rainfall. Rain falls for 8.2 days and accumulates 1.57" (40mm) of precipitation.

How many days does it rain in December in Forest Park?

In December, the rain falls for 8.2 days. Throughout December, 1.57" (40mm) of precipitation is accumulated.

How many days does it snow in December?

In December, in Forest Park, it is snowing for 8.3 days. Throughout December, 2.52" (64mm) 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 12min of daylight.

What is the average length of the day in December?

In Forest Park, Illinois, the average day length in December is 9h and 11min.

What time are sunrise and sunset in December in Forest Park?

On the first day of December, sunrise is at 7:00 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:30 pm CST.

How many hours of sunshine does Forest Park have in December?

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

What is the month with the lowest UV index?

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

What is the UV index intensity in December?

The average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health threat 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
Forest Park, IL

Average temperature in December - Forest Park, IL
  • Average high temperature in December: 35.1°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (28.9°F).

  • Average low temperature in December: 26.6°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 (19.4°F).

Average pressure in December
Forest Park, IL

Average pressure in December - Forest Park, 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
Forest Park, IL

Average wind speed in December - Forest Park, IL
  • Average wind speed in December: 10.4mph

The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).

Average humidity in December
Forest Park, IL

Average humidity in December - Forest Park, IL
  • Average humidity in December: 80%

The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Forest Park, IL

Average rainfall in December - Forest Park, IL
  • Average rainfall in December: 1.57"

The wettest month (with the highest rainfall) is May (4.49").
The driest month (with the least rainfall) is December (1.57").

Average rainfall days in December
Forest Park, IL

Average rainfall days in December - Forest Park, IL
  • Average rainfall days in December: 8.2 days

The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is February (5.1 days).

Average snowfall in December
Forest Park, IL

Average snowfall in December - Forest Park, IL
  • Average snowfall in December: 2.52"

The month with the highest snowfall is February (4.69").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Forest Park, IL

Average snowfall days in December - Forest Park, IL
  • Average snowfall days in December: 8.3 days

The month with the highest number of snowfall days is January (10.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Forest Park, IL

Average daylight in December / Average sunshine in December - Forest Park, 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 August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in December
Forest Park, IL

Average sunshine days in December - Forest Park, IL
  • Average sunshine days in December: 16.7 days

The month with the most sunshine days is December (16.7 days).
The month with the least sunshine days is July (9.9 days).

Average UV index in December
Forest Park, IL

Average UV index in December - Forest Park, 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
Forest Park, IL

Average cloud cover in December - Forest Park, IL
  • Average cloud cover in December: 58

The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December
Forest Park, IL

Average visibility in December - Forest Park, 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).

Forest Park, Illinois, USA

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