September Weather in Waterloo, Canada

Last updated: June 18, 2025

In September, the average temperature in Waterloo, Canada hovers around 16°C (62°F). However, be prepared for a range, as temperatures can dip to a chilly 0°C (32°F) and soar up to a warm 31°C (88°F). Expect about 75 mm (3.0 in) of precipitation spread across 10 days, contributing to an average humidity of 81%.

September Temperature in Waterloo

In September in Waterloo, the average temperature is 16°C (62°F). Maximums can reach 31°C (88°F), while minimums can drop as low as 0°C (32°F). Be prepared for a variety of weather conditions when traveling during this time.

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

The chart illustrates September 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, September typically has an average temperature of 16°C (62°F), with highs reaching up to 31°C (88°F) and lows dropping to around 0°C (32°F).

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

September Precipitation in Waterloo

In Waterloo in September, the precipitation amount is 75 mm (3.0 in) spread over a duration of 10 days.

September Precipitation Trends in Waterloo

The chart displays monthly precipitation patterns in Waterloo, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Waterloo, September typically receives around 75 mm (3.0 inches) of precipitation spread over approximately 10 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Waterloo

In Waterloo in September, humidity is 81%. With an average temperature of 16°C (62°F), this humidity feels like a warm embrace that can quickly leave travelers feeling sticky and drained, making outdoor adventures a bit challenging unless they stay properly hydrated and take breaks in the shade.

September Average Humidity in Waterloo

This chart illustrates the average monthly humidity levels in Waterloo, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Waterloo is approximately 81%, offering insight into how humid the weather typically is during this month.

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

September UV Index in Waterloo

In Waterloo in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Waterloo.

Maximum UV Index Levels in Waterloo for September

The chart shows the monthly maximum UV Index (UVI) for Waterloo in September, 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 September, the maximum UV index in Waterloo typically reaches 7, which falls under the high exposure category.

Data source: Waterloo September 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 September 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 September’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 September’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