October Weather in Ontario, United States

Last updated: June 24, 2025

In October, the average temperature in Ontario, United States hovers around 10°C (50°F). Expect a comfortable range with minimums dipping to -5°C (23°F) and maximums rising to 29°C (85°F). This month typically sees 115 mm (4.5 inches) of precipitation over about 12 days, resulting in an average humidity level of 79%.

October Temperature in Ontario

In October in Ontario, the average temperature is 10°C (50°F). The maximum can reach 29°C (85°F), while the minimum can drop as low as -5°C (23°F). Be prepared for a wide range of temperatures when traveling to Ontario during this time.

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

The chart illustrates October 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, October typically has an average temperature of 10°C (50°F), with highs reaching up to 29°C (85°F) and lows dropping to around -5°C (23°F).

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

October Precipitation in Ontario

In Ontario in October, the total precipitation amount is 115 mm (4.5 in) over a span of 12 days.

October Precipitation Trends in Ontario

The chart displays monthly precipitation patterns in Ontario, with values for each month alongside October’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how October’s conditions compare to those of other months. In Ontario, October typically receives around 115 mm (4.5 inches) of precipitation spread over approximately 12 days.

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

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Millimeters (mm) Inches (in)

October Humidity in Ontario

In Ontario in October humidity is 79%. With an average temperature of 10°C (50°F), this humidity feels like a damp chill that seeps into your bones, making outdoor exploration less inviting and requiring layered clothing to stay comfortable while traveling.

October Average Humidity in Ontario

This chart illustrates the average monthly humidity levels in Ontario, with October’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In October, average humidity in Ontario is approximately 79%, offering insight into how humid the weather typically is during this month.

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

October UV Index in Ontario

In Ontario in October, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Ontario.

Maximum UV Index Levels in Ontario for October

The chart shows the monthly maximum UV Index (UVI) for Ontario in October, 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 October, the maximum UV index in Ontario typically reaches 5, which falls under the moderate exposure category.

Data source: Ontario October 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 October 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 October’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 October’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (20°F)	40 mm (1.6 inches)	84%	low
February Weather	-6°C (21°F)	54 mm (2.1 inches)	85%	moderate
March Weather	2°C (35°F)	59 mm (2.3 inches)	84%	moderate
April Weather	7°C (45°F)	91 mm (3.6 inches)	83%	very high
May Weather	15°C (59°F)	141 mm (5.5 inches)	75%	very high
June Weather	21°C (70°F)	121 mm (4.8 inches)	79%	very high
July Weather	23°C (74°F)	110 mm (4.3 inches)	75%	very high
August Weather	21°C (70°F)	117 mm (4.6 inches)	69%	very high
September Weather	18°C (64°F)	112 mm (4.4 inches)	74%	very high
October Weather	10°C (50°F)	115 mm (4.5 inches)	79%	moderate
November Weather	2°C (35°F)	52 mm (2.0 inches)	88%	moderate
December Weather	-3°C (27°F)	46 mm (1.8 inches)	82%	low