March Weather in Ontario, United States

Last updated: June 24, 2025

In Ontario, United States, the average temperature in March hovers around 8°C (47°F), with a minimum dipping as low as -7°C (19°F) and a maximum reaching 27°C (81°F). Expect a total precipitation of 32 mm (1.3 in) spread over 9 days, and feel the average humidity at a notable 85%.

March Temperature in Ontario

In March in Ontario, the average temperature is 8°C (47°F). The maximum can reach 27°C (81°F), while the minimum can drop to as low as -7°C (19°F). This wide temperature range makes it essential for travelers to pack accordingly to enjoy their stay comfortably.

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

The chart illustrates March 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, March typically has an average temperature of 8°C (47°F), with highs reaching up to 27°C (81°F) and lows dropping to around -7°C (19°F).

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

March Precipitation in Ontario

In Ontario in March, the precipitation amount is 32 mm (1.3 in) over the course of 9 days.

March Precipitation Trends in Ontario

The chart displays monthly precipitation patterns in Ontario, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In Ontario, March typically receives around 32 mm (1.3 inches) of precipitation spread over approximately 9 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

March Humidity in Ontario

In Ontario in March humidity is 85%. With an average temperature of 8°C (47°F), this humidity feels like a chilly dampness that clings to your skin, making outdoor activities feel less refreshing and more uncomfortable for traveling.

March Average Humidity in Ontario

This chart illustrates the average monthly humidity levels in Ontario, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in Ontario is approximately 85%, offering insight into how humid the weather typically is during this month.

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

March UV Index in Ontario

In Ontario in March, 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 March

The chart shows the monthly maximum UV Index (UVI) for Ontario in March, 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 March, the maximum UV index in Ontario typically reaches 6, which falls under the high exposure category.

Data source: Ontario March 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 March 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 March’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 March’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