The best times to visit Ontario for ideal weather are
March 5th to June 17th
September 24th to November 25th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Ontario Travel Guide
Other Ontario Travel Info
Weather in Ontario
Average temperatures in Ontario vary greatly. Considering humidity, temperatures feel very nice much of the year, but hot in the summer and cold in the winter with a very low chance of rain or snow throughout the year. The area is more temperate than most — in the 61st percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Ontario, the hottest months are August, September, and then July. See average monthly temperatures below. The warmest time of year is generally late August to early September where highs are regularly around 98.4°F (36.9°C) with temperatures rarely dropping below 68.6°F (20.3°C) at night.
Ontario Temperatures (Fahrenheit)
Ontario Temperatures (Celsius)
The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.
Ontario Perceived Temperature (F)
Ontario Perceived Temperature (C)
Average Ontario Temperatures by Month
Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Ontario are June, July, and then August. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early May. For example, on the week of April 30th there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in mid December with an average of 2 days of significant precipitation the week of December 17th.
When can you find snow in Ontario? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Ontario.
Snow on the Ground
The graph below shows the average snow on the ground in Ontario (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
Humidity and Wind
Ontario has some comfortably humid months, and slightly dry months in the opposite season. The least humid month is January (34.9% relative humidity), and the most humid month is February (46.3%).
Wind in Ontario is usually calm. The windiest month is May, followed by April and June. May’s average wind speed of around 6.2 knots (7.2 MPH or 11.5 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early May where average top sustained speeds reach 15.3 knots, which is considered a moderate breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Ontario.
The graph below shows wind speed (max and average) in knots.
Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
|Month||Avg. Wind||Avg. Wind Feel||Sustained High Wind||High Wind Feel|
|Jan||4.3||Light breeze||11.4||Significant breeze|
|Feb||4.2||Light breeze||11.6||Significant breeze|
|Mar||4.8||Light breeze||12.6||Significant breeze|
|Apr||5.9||Light breeze||14.1||Significant breeze|
|May||6.2||Light breeze||14||Significant breeze|
|Jun||5.9||Light breeze||13.3||Significant breeze|
|Jul||5.8||Light breeze||13.4||Significant breeze|
|Aug||5.3||Light breeze||13.2||Significant breeze|
|Sep||4.7||Light breeze||12.8||Significant breeze|
|Oct||4.5||Light breeze||11.7||Significant breeze|
|Nov||3.6||Barely noticeable||10.2||Significant breeze|
|Dec||3.5||Barely noticeable||9.6||Gentle breeze|
Show Relative Humidity by Month
|Month||Avg. Relative Humidity|
Is it Safe to Travel to Ontario?
Our best data indicates this area is generally safe. As of Oct 07, 2019 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Sep 23, 2019.
The Busiest and Least Crowded Months
The busiest month for tourism in Ontario, CA, US is July, followed by June and May. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Ontario in December. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
Overall Ontario Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderate. Highs range from 83.7°F (28.7°C) and 69.3°F (20.7°C) with warmer temperatures in the later months. Rain is rare with 1 to 2 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.
Summer (June through August)
The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the least precipitation with about 0 days of precipitation per month. June – August is the busiest season for tourism in Ontario, so lodging and other accommodations may cost more than usual.
Fall (September through November)
Fall daily highs range from 95.9°F (35.5°C) and 72°F (22.2°C), which will feel very nice given the humidity and wind. It rains or snows a normal amount: 0 to 2 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.
Winter (December through February)
Weather is somewhat cool this time of year in Ontario to be enjoyable for warm weather travelers. The average high during this season is between 71.9°F (22.2°C) and 64.3°F (17.9°C). On average, it rains or snows a fair amount: 3 to 5 times per month. These times of year are fairly slow with tourists.