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October Weather in Ontario, United States

Last updated: June 24, 2025

In Ontario, United States, the average temperature in October hovers around 14°C (57°F). Expect a range where the minimum dips to -2°C (28°F) and the maximum can soar to 32°C (89°F). With an average precipitation of 98 mm (3.9 in) spread over 13 days, you might want to keep an umbrella handy! Additionally, the average humidity sits at a cozy 82%, creating a distinctive climate to experience.

October Temperature in Ontario

In October in Ontario, the average temperature is 14°C (57°F). The maximum can reach 32°C (89°F) and the minimum can be as low as -2°C (28°F). Be prepared for a wide range of temperatures while traveling, making it essential to pack accordingly for both warm and chilly conditions.

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 14°C (57°F), with highs reaching up to 32°C (89°F) and lows dropping to around -2°C (28°F).
JanFebMarAprMayJunJulAugSepOctNovDec293240506270747267564135
Data source: Temperature data for Ontario 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.

October Precipitation in Ontario

In Ontario in October, the precipitation amount is 98 mm (3.9 in) over a span of 13 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 98 mm (3.9 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec81981031301261411238980989292
Data source: Precipitation data for October generated using information from the Copernicus Climate Change Service.
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October Humidity in Ontario

In Ontario in October, humidity is 82%. With an average temperature of 14°C (57°F), this humidity feels like a thick blanket enveloping you, making outdoor activities uncomfortable and travel more challenging due to the heavy, damp air.

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 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%87%88%81%82%81%78%78%82%89%86%
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 is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Ontario, you can refer to this 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 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356810101098642
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.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)81 mm (3.2 inches)88%moderate
February Weather0°C (32°F)98 mm (3.8 inches)87%moderate
March Weather5°C (40°F)103 mm (4.1 inches)87%high
April Weather10°C (50°F)130 mm (5.1 inches)87%very high
May Weather17°C (62°F)126 mm (5.0 inches)81%very high
June Weather21°C (71°F)141 mm (5.5 inches)82%very high
July Weather24°C (75°F)123 mm (4.8 inches)81%very high
August Weather22°C (72°F)89 mm (3.5 inches)78%very high
September Weather20°C (67°F)80 mm (3.2 inches)78%very high
October Weather14°C (57°F)98 mm (3.9 inches)82%high
November Weather5°C (41°F)92 mm (3.6 inches)89%moderate
December Weather1°C (35°F)92 mm (3.6 inches)86%low

Compare Ontario's Climate with Cities Worldwide