December Weather in Joliet, United States

Last updated: June 24, 2025

In December, the average temperature in Joliet, United States hovers around -3°C (28°F). However, temperatures can vary significantly, with a minimum of -25°C (-13°F) and a maximum reaching 18°C (64°F). Expect about 30 mm (1.2 in) of precipitation over 7 days, and be prepared for high average humidity at 87%.

December Temperature in Joliet

In December in Joliet, the average temperature is -3°C (28°F), with maximums reaching 18°C (64°F) and minimums dropping as low as -25°C (-13°F). Be sure to pack warm clothing and prepare for a range of temperatures while traveling.

December Weather in Joliet: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Joliet, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Joliet, December typically has an average temperature of -3°C (28°F), with highs reaching up to 18°C (64°F) and lows dropping to around -25°C (-13°F).

Data source: Temperature data for Joliet generated using information from the Copernicus Climate Change Service.

December Precipitation in Joliet

In Joliet in December, the total precipitation amount is 30 mm (1.2 in) over a span of 7 days.

December Precipitation Trends in Joliet

The chart displays monthly precipitation patterns in Joliet, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Joliet, December typically receives around 30 mm (1.2 inches) of precipitation spread over approximately 7 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Joliet

In Joliet in December humidity is 87%. With an average temperature of -3°C (28°F), this humidity feels like a biting chill that clings to your skin, making travel quite uncomfortable and forcing you to bundle up extra just to stay warm.

December Average Humidity in Joliet

This chart illustrates the average monthly humidity levels in Joliet, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Joliet is approximately 87%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Joliet

In Joliet in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Joliet, you can visit Hourly UV Index in Joliet.

Maximum UV Index Levels in Joliet for December

The chart shows the monthly maximum UV Index (UVI) for Joliet in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Joliet typically reaches 2, which falls under the low exposure category.

Data source: Joliet December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How December Weather in Joliet Compares to Other Months

Weather in Joliet varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Joliet, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Joliet, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	21 mm (0.8 inches)	85%	moderate
February Weather	-7°C (20°F)	46 mm (1.8 inches)	85%	moderate
March Weather	2°C (35°F)	44 mm (1.7 inches)	79%	high
April Weather	5°C (42°F)	76 mm (3.0 inches)	74%	very high
May Weather	12°C (53°F)	82 mm (3.2 inches)	76%	very high
June Weather	18°C (64°F)	76 mm (3.0 inches)	79%	extreme
July Weather	22°C (72°F)	32 mm (1.3 inches)	81%	very high
August Weather	21°C (69°F)	25 mm (1.0 inches)	80%	very high
September Weather	15°C (60°F)	57 mm (2.2 inches)	76%	very high
October Weather	6°C (43°F)	57 mm (2.2 inches)	74%	moderate
November Weather	1°C (35°F)	34 mm (1.3 inches)	81%	moderate
December Weather	-3°C (28°F)	30 mm (1.2 inches)	87%	low