May Weather in Waterloo, Canada

Last updated: June 18, 2025

In May, the average temperature in Waterloo, Canada hovers around 13°C (56°F). However, temperatures can swing dramatically, with a minimum of -4°C (26°F) and a maximum reaching up to 31°C (89°F). Expect about 98 mm (3.8 in) of precipitation over 13 days, and enjoy the elevated humidity level of 82% as it contributes to the region's unique climate.

May Temperature in Waterloo

In May in Waterloo, the average temperature is 13°C (56°F). Maximums can reach 31°C (89°F), while minimums can drop to as low as -4°C (26°F). Pack for a range of weather conditions to fully enjoy your trip!

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

The chart illustrates May temperature patterns in Waterloo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Waterloo, May typically has an average temperature of 13°C (56°F), with highs reaching up to 31°C (89°F) and lows dropping to around -4°C (26°F).

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

May Precipitation in Waterloo

In Waterloo in May, the precipitation amount is 98 mm (3.8 in) spread over 13 days.

May Precipitation Trends in Waterloo

The chart displays monthly precipitation patterns in Waterloo, 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 Waterloo, May typically receives around 98 mm (3.8 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 Waterloo

In Waterloo in May, humidity is 82%. With an average temperature of 13°C (56°F), this humidity feels like a damp blanket wrapping around you, making it feel much cooler than it is and creating a heavy atmosphere that can be exhausting for travelers.

May Average Humidity in Waterloo

This chart illustrates the average monthly humidity levels in Waterloo, 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 Waterloo is approximately 82%, 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 Waterloo

In Waterloo 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 Waterloo.

Maximum UV Index Levels in Waterloo for May

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

Data source: Waterloo 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 Waterloo Compares to Other Months

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

This table compares monthly weather conditions in Waterloo, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (23°F)	73 mm (2.9 inches)	90%	low
February Weather	-5°C (24°F)	77 mm (3.0 inches)	90%	moderate
March Weather	0°C (32°F)	67 mm (2.6 inches)	87%	moderate
April Weather	5°C (42°F)	100 mm (3.9 inches)	87%	very high
May Weather	13°C (56°F)	98 mm (3.8 inches)	82%	very high
June Weather	18°C (66°F)	104 mm (4.1 inches)	81%	very high
July Weather	21°C (71°F)	75 mm (3.0 inches)	79%	very high
August Weather	20°C (69°F)	97 mm (3.8 inches)	80%	very high
September Weather	16°C (62°F)	75 mm (3.0 inches)	81%	high
October Weather	10°C (50°F)	104 mm (4.1 inches)	84%	moderate
November Weather	2°C (36°F)	83 mm (3.3 inches)	88%	moderate
December Weather	-2°C (29°F)	74 mm (2.9 inches)	87%	low