Weather in Ontario in August 2025
- August is usually the hottest month of the year in Ontario;
Average weather
Average temperature in Ontario in August
The temperature in August is +93°F on average, with a range between a maximum of +102°F during the day and a minimum of +63°F at night.
The average maximum temperature goes up 5% by the end of the month, compared with the beginning of the month, from +93°F to +95°F.
Is Ontario warm or cold in August?
Ontario is typically hot in August.
Maximum temperatures go up compared to the previous month from +91°F to +93°F. The minimum temperature also goes up from +66°F to +66°F.
Make sure that you pack your summer linen and swimming costumes; it’s probably going to be hot.
August is the hottest month in Ontario, here is the comparison with other months:
Climate in Ontario in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +91°F | +93°F | +90°F | ||||
| Min. temperature | ||||||
| +52°F | +57°F | +50°F | ||||
| Max. temperature | ||||||
| +115°F | +111°F | +115°F | ||||
| Rainfall | ||||||
| 2 mm | 4 mm | 7 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 58% | 56% | 57% | ||||
| Air pressure | ||||||
| 1012 HPa | 1011 HPa | 1011 HPa | ||||
| Sunny days | ||||||
| 14 | 16 | 14 | ||||
| Cloudy days | ||||||
| 16 | 13 | 13 | ||||
| Rainy days | ||||||
| 1 | 1 | 3 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as good as in July. It’s getting warmer as August arrives. The average maximum temperature goes up from +91°F to +93°F during the day. Prepare for more rain. Average rainfall goes from 2 mm to 4 mm. It feels drier, as humidity decreases from 58% to 56%. The average wind speed doesn’t change much during August, staying around 2 m/s. The good news is there are likely to be more sunny days in August, from 14 to 16.
But maybe it is worth considering traveling in September as the weather gets better.
Wind
The average wind speed is 3 m/s getting up to 4 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Ontario is gradually decreasing during August, going from 4 m/s to 3 m/s over the course of the month.
Rain
How was the weather last August in Ontario?
Climate Change Over the Years
The climate in Ontario in August has not changed that much over the last 43 years.
The average temperature was the lowest in 1998 (+74°F) and the highest in 2014 (+82°F). The driest year was 1989 with only 153 mm of rainfall, and the wettest year was 2022 with 1158 mm.
FAQ
Is August a good time to visit Ontario?
Can you sunbathe in Ontario in August?
Is Ontario rainy in August?
Is it sunny in Ontario in August?
Other cities in USA
Monthly weather in Ontario
Source of the data
For this page, we’ve looked at the typical weather in Ontario, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
