December weather forecast
Willowbrook, IL

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Weather in December

December, the first month of the winter in Willowbrook, is also an icy month, with an average temperature ranging between min 25.5°F (-3.6°C) and max 35.2°F (1.8°C).

Temperature

In December, the average high-temperature decreases from a frosty 46.2°F (7.9°C) in November to an icy 35.2°F (1.8°C). Willowbrook anticipates an average minimum temperature of 25.5°F (-3.6°C) in the month of December.

Humidity

In December, the average relative humidity is 80%.

Rainfall

The months with the least rainfall are November and December Rain falls for 8.5 days and accumulates 1.77" (45mm) of rain.

Snowfall

January through April, October through December are months with snowfall. In Willowbrook, during December, snow falls for 9.6 days and regularly aggregates up to 2.76" (70mm) of snow. Throughout the year, in Willowbrook, Illinois, there are 47.1 snowfall days, and 19.02" (483mm) of snow is accumulated.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year in Willowbrook.
On the first day of the month, sunrise is at 7:00 am and sunset at 4:21 pm. On the last day of December, in Willowbrook, sunrise is at 7:18 am and sunset at 4:31 pm CST.

Sunshine

In Willowbrook, Illinois, the average sunshine in December is 4.1h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index in Willowbrook. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum high UV index of 1 in December translates into the following recommendations:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Willowbrook?

During December, Willowbrook experiences an average high-temperature of 35.2°F (1.8°C) and a low-temperature of 25.5°F (-3.6°C). In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, is computed to be 84.2°F (29°C).

What is the average humidity in December in Willowbrook?

The average relative humidity in December in Willowbrook, Illinois, is 80%.

What is the driest month in Willowbrook?

November and December are months with the least rain in Willowbrook, Illinois, when the rain falls for 8.5 days and typically aggregates up to 1.77" (45mm) of rain.

How many days does it rain in December in Willowbrook?

In Willowbrook, during December, the rain falls for 8.5 days and regularly aggregates up to 1.77" (45mm) of precipitation.

How many days does it snow in December in Willowbrook?

In Willowbrook, during December, snow falls for 9.6 days and regularly aggregates up to 2.76" (70mm) of snow.

What is the month with the shortest days in Willowbrook?

The month with the shortest days in Willowbrook, Illinois, is December, with an average of 9h and 12min of daylight.

What is the average length of the day in December in Willowbrook?

In December, the average day length in Willowbrook, Illinois, is 9h and 12min.

When are sunrise and sunset in December in Willowbrook?

In December, on the first day of the month, sunrise is at 7:00 am and sunset at 4:21 pm. On the last day of the month, in Willowbrook, Illinois, sunrise is at 7:18 am and sunset at 4:31 pm CST.

How long on average sun shines in December in Willowbrook?

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

When is the lowest UV index in Willowbrook?

The month with the lowest UV index in Willowbrook, Illinois, is December, with an average maximum UV index of 1.

What is the UV index intensity in December in Willowbrook?

The average daily maximum UV index in December in Willowbrook is 1. A UV Index value of 2, and less, symbolizes 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
Willowbrook, IL

Average temperature in December - Willowbrook, IL
  • Average high temperature in December: 35.2°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.9°F).

  • Average low temperature in December: 25.5°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).

Average pressure in December
Willowbrook, IL

Average pressure in December - Willowbrook, 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
Willowbrook, IL

Average wind speed in December - Willowbrook, IL
  • Average wind speed in December: 9.4mph

The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).

Average humidity in December
Willowbrook, IL

Average humidity in December - Willowbrook, IL
  • Average humidity in December: 80%

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

Average rainfall in December
Willowbrook, IL

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

The wettest month (with the highest rainfall) is May (4.61").
The driest months (with the least rainfall) are November and December (1.77").

Average rainfall days in December
Willowbrook, IL

Average rainfall days in December - Willowbrook, IL
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is June (19.4 days).
The month with the least rainy days is February (5.9 days).

Average snowfall in December
Willowbrook, IL

Average snowfall in December - Willowbrook, IL
  • Average snowfall in December: 2.76"

The month with the highest snowfall is February (5.28").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Willowbrook, IL

Average snowfall days in December - Willowbrook, IL
  • Average snowfall days in December: 9.6 days

The month with the highest number of snowfall days is January (13.3 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
Willowbrook, IL

Average daylight in December / Average sunshine in December - Willowbrook, 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 18min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in December
Willowbrook, IL

Average sunshine days in December - Willowbrook, IL
  • Average sunshine days in December: 14.3 days

The month with the most sunshine days is November (16.1 days).
The month with the least sunshine days is June (8.2 days).

Average UV index in December
Willowbrook, IL

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

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

Average cloud cover in December
Willowbrook, IL

Average cloud cover in December - Willowbrook, 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 29).

Average visibility in December
Willowbrook, IL

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

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

Willowbrook, Illinois, USA

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