January Weather in Joliet, United States

Last updated: June 24, 2025

In January, the average temperature in Joliet, United States hovers around -4°C (25°F), with potential extremes reaching as low as -27°C (-17°F) and peaking at 13°C (56°F). Visitors should prepare for 21 mm (0.8 in) of precipitation spread over approximately 5 days, and expect an elevated average humidity of 85%.

January Temperature in Joliet

In January in Joliet, the average temperature is -4°C (25°F), with maximums reaching 13°C (56°F) and minimums dropping as low as -27°C (-17°F). It's essential to dress warmly and prepare for variable weather if you're planning to travel during this time.

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

The chart illustrates January 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, January typically has an average temperature of -4°C (25°F), with highs reaching up to 13°C (56°F) and lows dropping to around -27°C (-17°F).

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

January Precipitation in Joliet

In Joliet in January, the precipitation amount is 21 mm (0.8 in) spread over a period of 5 days.

January Precipitation Trends in Joliet

The chart displays monthly precipitation patterns in Joliet, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Joliet, January typically receives around 21 mm (0.8 inches) of precipitation spread over approximately 5 days.

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

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Millimeters (mm) Inches (in)

January Humidity in Joliet

In Joliet in January, humidity is 85%. With an average temperature of -4°C (25°F), this humidity feels like a damp chill clinging to your skin, making travel outside uncomfortable and leaving you feeling cold and clammy despite the freezing temperatures.

January Average Humidity in Joliet

This chart illustrates the average monthly humidity levels in Joliet, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Joliet is approximately 85%, offering insight into how humid the weather typically is during this month.

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

January UV Index in Joliet

In Joliet in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Joliet, you can check the information here.

Maximum UV Index Levels in Joliet for January

The chart shows the monthly maximum UV Index (UVI) for Joliet in January, 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 January, the maximum UV index in Joliet typically reaches 3, which falls under the moderate exposure category.

Data source: Joliet January 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 January 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 January’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 January’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