July Weather in Ontario, United States

Last updated: June 24, 2025

In Ontario, United States, the average temperature in July is a warm 29°C (84°F). Expect the mercury to dip as low as 10°C (51°F) and soar to a sweltering 43°C (109°F). Fortunately, rainfall is minimal, with only 1 mm (0.0 in) expected over 0 days. The average humidity sits around a comfortable 66%, making for pleasant conditions overall.

July Temperature in Ontario

In July in Ontario, the average temperature is 29°C (84°F), with maximums reaching up to 43°C (109°F) and minimums dropping to as low as 10°C (51°F). It's essential to pack for diverse weather conditions when traveling to this destination.

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

The chart illustrates July temperature patterns in Ontario, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ontario, July typically has an average temperature of 29°C (84°F), with highs reaching up to 43°C (109°F) and lows dropping to around 10°C (51°F).

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

July Precipitation in Ontario

In Ontario in July, the precipitation amount is 1 mm (0.0 in) during a span of 0 days.

July Precipitation Trends in Ontario

The chart displays monthly precipitation patterns in Ontario, 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 Ontario, July typically receives around 1 mm (0.0 inches) of precipitation spread over approximately 0 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 Ontario

In Ontario in July, humidity is 66%. With an average temperature of 29°C (84°F), this humidity feels like a warm and sticky embrace that can make outdoor activities quite uncomfortable, often prompting travelers to seek shade or relief in air-conditioned spaces.

July Average Humidity in Ontario

This chart illustrates the average monthly humidity levels in Ontario, 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 Ontario is approximately 66%, 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 Ontario

In Ontario in July, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Ontario.

Maximum UV Index Levels in Ontario for July

The chart shows the monthly maximum UV Index (UVI) for Ontario 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 Ontario typically reaches 10, which falls under the very high exposure category.

Data source: Ontario 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 Ontario Compares to Other Months

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

This table compares monthly weather conditions in Ontario, showing how July’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	0°C (33°F)	42 mm (1.7 inches)	88%	moderate
February Weather	2°C (36°F)	46 mm (1.8 inches)	89%	moderate
March Weather	8°C (47°F)	32 mm (1.3 inches)	85%	high
April Weather	12°C (55°F)	23 mm (0.9 inches)	79%	high
May Weather	17°C (64°F)	28 mm (1.1 inches)	71%	very high
June Weather	23°C (73°F)	16 mm (0.6 inches)	71%	extreme
July Weather	29°C (84°F)	1 mm (0.0 inches)	66%	very high
August Weather	27°C (82°F)	5 mm (0.2 inches)	50%	very high
September Weather	21°C (70°F)	10 mm (0.4 inches)	48%	very high
October Weather	12°C (55°F)	16 mm (0.6 inches)	65%	moderate
November Weather	6°C (43°F)	27 mm (1.1 inches)	84%	moderate
December Weather	1°C (35°F)	29 mm (1.1 inches)	87%	low