May Weather in Waterloo, Canada

Last updated: June 18, 2025

In May, the average temperature in Waterloo, Canada hovers around 13°C (55°F), with a wide range where the minimum can dip to -1°C (30°F) and the maximum can soar to 35°C (95°F). Expect about 106 mm (4.2 in) of precipitation spread over 13 days, contributing to an average humidity of 80%.

May Temperature in Waterloo

In May in Waterloo, the average temperature is 13°C (55°F). Maximum temperatures can reach 35°C (95°F), while minimums can drop as low as -1°C (30°F). This varied climate makes Waterloo an intriguing destination for travelers, offering both warm days and chilly nights to experience.

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 (55°F), with highs reaching up to 35°C (95°F) and lows dropping to around -1°C (30°F).
JanFebMarAprMayJunJulAugSepOctNovDec172028415563696759483323
Data source: Temperature data for Waterloo generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Waterloo

In Waterloo in May, the precipitation amount is 106 mm (4.2 in) spread over a duration of 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 106 mm (4.2 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec9389901201071261231288414712586
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Waterloo

In Waterloo in May humidity is 80%. With an average temperature of 13°C (55°F), this humidity feels like a damp blanket wrapping around you, making any outdoor activity feel stifling and heavy, which can lead to fatigue for travelers unaccustomed to such moist conditions.

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 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec93%92%86%85%80%74%76%75%78%86%89%89%
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.
JanFebMarAprMayJunJulAugSepOctNovDec245799987532
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.
 TemperaturePrecipitationHumidityUV
January Weather-8°C (18°F)93 mm (3.7 inches)93%low
February Weather-7°C (20°F)89 mm (3.5 inches)92%moderate
March Weather-2°C (28°F)90 mm (3.5 inches)86%moderate
April Weather5°C (42°F)120 mm (4.7 inches)85%high
May Weather13°C (55°F)106 mm (4.2 inches)80%very high
June Weather17°C (64°F)126 mm (5.0 inches)74%very high
July Weather20°C (69°F)123 mm (4.8 inches)76%very high
August Weather19°C (67°F)128 mm (5.0 inches)75%very high
September Weather15°C (60°F)84 mm (3.3 inches)78%high
October Weather9°C (49°F)147 mm (5.8 inches)86%moderate
November Weather1°C (33°F)125 mm (4.9 inches)88%moderate
December Weather-5°C (23°F)86 mm (3.4 inches)89%low

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