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.



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)


“Feels-Like” Temperatures

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.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 70.3 56.5 44.2
Feb 69.1 55.9 45.1
Mar 74.9 60.2 48.6
Apr 77.2 62.2 51.1
May 81.3 66.1 55.4
Jun 87.2 70.9 59.4
Jul 92.4 76.2 64.4
Aug 95.1 78.1 65.4
Sep 93.4 76.5 64.2
Oct 84.3 69 57.2
Nov 75.9 61 48.6
Dec 66.4 53.9 42.9

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 21.3 13.6 6.8
Feb 20.6 13.3 7.3
Mar 23.8 15.7 9.2
Apr 25.1 16.8 10.6
May 27.4 18.9 13
Jun 30.7 21.6 15.2
Jul 33.6 24.6 18
Aug 35.1 25.6 18.6
Sep 34.1 24.7 17.9
Oct 29.1 20.6 14
Nov 24.4 16.1 9.2
Dec 19.1 12.2 6.1



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.

Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Ontario (in).

Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 10% 0 1.9
Feb 15% 0 2
Mar 7% 0 1
Apr 4% 0 0.6
May 3% 0 0.3
Jun 0% 0 0
Jul 1% 0 0.1
Aug 1% 0 0.1
Sep 1% 0 0.2
Oct 4% 0 0.4
Nov 7% 0 0.7
Dec 17% 0 2.9

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 10 0 4.8
Feb 15 0 5.1
Mar 7 0 2.5
Apr 4 0 1.5
May 3 0 0.8
Jun 0 0 0
Jul 1 0 0.3
Aug 1 0 0.3
Sep 1 0 0.5
Oct 4 0 1
Nov 7 0 1.8
Dec 17 0 7.4


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.

Avg. Relative Humidity


The graph below shows wind speed (max and average) in knots.

Max Sustained Wind
Average Daily Wind

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
Jan 34.9%
Feb 46.3%
Mar 42.2%
Apr 42.1%
May 45.4%
Jun 46.2%
Jul 42.6%
Aug 38.3%
Sep 37.9%
Oct 39.6%
Nov 38.4%
Dec 44.5%


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

Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is slightly extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 67.6 in December means 67.6% of the tourists vs. July.



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.


Best Times to Travelthe United States › Ontario, CA, US