December weather forecast
Chicago Heights, IL

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Weather in December

The first month of the winter, December, is still a cold month in Chicago Heights, Illinois, with an average temperature ranging between max 35.6°F (2°C) and min 25.9°F (-3.4°C).

Temperature

Chicago Heights's December weather features a mild decline in high-temperatures, reducing from a chilly 46.9°F (8.3°C) in November to a cold 35.6°F (2°C). Chicago Heights records an average nighttime low-temperature of 25.9°F (-3.4°C) throughout December.

Humidity

In Chicago Heights, the average relative humidity in December is 81%.

Rainfall

December is the month with the least rainfall. Rain falls for 7.9 days and accumulates 1.54" (39mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In December, it is snowing for 9.1 days. Throughout December, 2.76" (70mm) of snow is accumulated. In Chicago Heights, during the entire year, snow falls for 44.6 days and aggregates up to 16.46" (418mm) of snow.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 6:58 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:30 pm CST.

Sunshine

In December, the average sunshine in Chicago Heights is 4h.

UV index

December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the average person.
Note: The UV index of 1 during December leads to these advisories:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

The high-temperature, in December, in Chicago Heights, is 35.6°F (2°C), while the low-temperature averages to 25.9°F (-3.4°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in July is evaluated at 87.8°F (31°C).

What is the average humidity in December?

The average relative humidity in December in Chicago Heights is 81%.

What is the driest month?

The month with the least rainfall is December, when the rain falls for 7.9 days and typically collects 1.54" (39mm) of precipitation.

How many days does it rain in December?

In Chicago Heights, in December, during 7.9 rainfall days, 1.54" (39mm) of precipitation is typically accumulated.

How much does it snow in Chicago Heights in December?

In Chicago Heights, in December, during 9.1 snowfall days, 2.76" (70mm) of snow is typically 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 December, the average day length is 9h and 14min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:58 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:30 pm CST.

How long on average sun shines in December?

The average sunshine duration in December is 4h.

When is the lowest UV index?

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

How high is the UV index in December?

In Chicago Heights, the average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes a low health threat from unprotected exposure to 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
Chicago Heights, IL

Average temperature in December - Chicago Heights, IL
  • Average high temperature in December: 35.6°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in December: 25.9°F

The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in December
Chicago Heights, IL

Average pressure in December - Chicago Heights, IL
  • Average pressure in December: 30.1"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
Chicago Heights, IL

Average wind speed in December - Chicago Heights, IL
  • Average wind speed in December: 9.5mph

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
Chicago Heights, IL

Average humidity in December - Chicago Heights, IL
  • Average humidity in December: 81%

The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is October (73%).

Average rainfall in December
Chicago Heights, IL

Average rainfall in December - Chicago Heights, IL
  • Average rainfall in December: 1.54"

The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is December (1.54").

Average rainfall days in December
Chicago Heights, IL

Average rainfall days in December - Chicago Heights, IL
  • Average rainfall days in December: 7.9 days

The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (6.1 days).

Average snowfall in December
Chicago Heights, IL

Average snowfall in December - Chicago Heights, IL
  • Average snowfall in December: 2.76"

The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Chicago Heights, IL

Average snowfall days in December - Chicago Heights, IL
  • Average snowfall days in December: 9.1 days

The month with the highest number of snowfall days is January (12.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Chicago Heights, IL

Average daylight in December / Average sunshine in December - Chicago Heights, 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 0min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

Average sunshine days in December
Chicago Heights, IL

Average sunshine days in December - Chicago Heights, IL
  • Average sunshine days in December: 15 days

The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is April (10.2 days).

Average UV index in December
Chicago Heights, IL

Average UV index in December - Chicago Heights, 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
Chicago Heights, IL

Average cloud cover in December - Chicago Heights, 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 August (Cloud cover 30).

Average visibility in December
Chicago Heights, IL

Average visibility in December - Chicago Heights, IL
  • Average visibility in December: 6mi

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

Chicago Heights, Illinois, USA

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