July Weather in Sarnia, Canada

Last updated: June 18, 2025

The average temperature in Sarnia, Canada during July is a pleasant 23°C (73°F). Expect minimums around 13°C (55°F) and maximums soaring up to 34°C (93°F). This month also brings 73 mm (2.9 in) of precipitation over 11 days, contributing to an average humidity level of 80%.

July Temperature in Sarnia

In July in Sarnia, the average temperature is 23°C (73°F). Maximum temperatures can reach 34°C (93°F) while minimums can drop as low as 13°C (55°F). This makes it an ideal time for travelers seeking pleasant weather for outdoor activities.

July Weather in Sarnia: Daily Temperature Highs, Lows, and Averages

The chart illustrates July temperature patterns in Sarnia, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sarnia, July typically has an average temperature of 23°C (73°F), with highs reaching up to 34°C (93°F) and lows dropping to around 13°C (55°F).

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

July Precipitation in Sarnia

In Sarnia in July, the precipitation amount is 73 mm (2.9 in), spread over 11 days.

July Precipitation Trends in Sarnia

The chart displays monthly precipitation patterns in Sarnia, with values for each month alongside July’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how July’s conditions compare to those of other months. In Sarnia, July typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 11 days.

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

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Millimeters (mm) Inches (in)

July Humidity in Sarnia

In Sarnia in July humidity is 80%. With an average temperature of 23°C (73°F), this humidity feels like a warm blanket enveloping you, making outdoor activities slightly sticky and requiring frequent breaks in shaded areas to stay comfortable while exploring.

July Average Humidity in Sarnia

This chart illustrates the average monthly humidity levels in Sarnia, with July’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In July, average humidity in Sarnia is approximately 80%, offering insight into how humid the weather typically is during this month.

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

July UV Index in Sarnia

In Sarnia in July, 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 Sarnia.

Maximum UV Index Levels in Sarnia for July

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

Data source: Sarnia July 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 July Weather in Sarnia Compares to Other Months

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

This table compares monthly weather conditions in Sarnia, showing how July’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	60 mm (2.4 inches)	88%	low
February Weather	-3°C (28°F)	66 mm (2.6 inches)	87%	moderate
March Weather	1°C (35°F)	63 mm (2.5 inches)	85%	moderate
April Weather	7°C (45°F)	95 mm (3.7 inches)	86%	very high
May Weather	13°C (57°F)	97 mm (3.8 inches)	80%	very high
June Weather	20°C (68°F)	86 mm (3.4 inches)	80%	very high
July Weather	23°C (73°F)	73 mm (2.9 inches)	80%	very high
August Weather	22°C (72°F)	79 mm (3.1 inches)	80%	very high
September Weather	18°C (65°F)	73 mm (2.9 inches)	80%	high
October Weather	12°C (54°F)	106 mm (4.2 inches)	84%	moderate
November Weather	4°C (40°F)	72 mm (2.8 inches)	89%	moderate
December Weather	0°C (33°F)	55 mm (2.2 inches)	86%	low