May Weather in Joliet, United States

Last updated: June 24, 2025

In Joliet, United States, the average temperature in May is a mild 12°C (53°F). However, temperatures can vary significantly, with a minimum of -3°C (28°F) and a maximum of 29°C (85°F). You'll likely experience wet conditions, as 82 mm (3.2 in) of precipitation falls over approximately 13 days. With an average humidity of 76%, be prepared for a damp atmosphere during your stay!

May Temperature in Joliet

In May in Joliet, the average temperature is 12°C (53°F). The maximum can reach 29°C (85°F), while the minimum can drop as low as -3°C (28°F). This diverse temperature range makes it essential for travelers to pack layers for their visit.

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

The chart illustrates May 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, May typically has an average temperature of 12°C (53°F), with highs reaching up to 29°C (85°F) and lows dropping to around -3°C (28°F).

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

May Precipitation in Joliet

In Joliet in May, the total precipitation amount is 82 mm (3.2 in), occurring over the course of 13 days.

May Precipitation Trends in Joliet

The chart displays monthly precipitation patterns in Joliet, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Joliet, May typically receives around 82 mm (3.2 inches) of precipitation spread over approximately 13 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Joliet

In Joliet in May humidity is 76%. With an average temperature of 12°C (53°F), this humidity feels like a damp chill that settles into your bones, making outdoor activities a bit uncomfortable and necessitating layers to stay warm while exploring.

May Average Humidity in Joliet

This chart illustrates the average monthly humidity levels in Joliet, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Joliet is approximately 76%, offering insight into how humid the weather typically is during this month.

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

May UV Index in Joliet

In Joliet in May, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Joliet.

Maximum UV Index Levels in Joliet for May

The chart shows the monthly maximum UV Index (UVI) for Joliet in May, 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 May, the maximum UV index in Joliet typically reaches 9, which falls under the very high exposure category.

Data source: Joliet May 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 May 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 May’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 May’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