Weather in Ontario in May 2026
Average weather
Average temperature in Ontario in May
The temperature in May is +73°F on average, with a range between a maximum of +86°F during the day and a minimum of +46°F at night.
The average maximum temperature goes down 18% by the end of the month, compared with the beginning of the month, from +72°F to +64°F.
Is Ontario warm or cold in May?
Ontario is typically warm in May.
Maximum temperatures go up compared to the previous month from +75°F to +79°F. The minimum temperature also goes up from +52°F to +55°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how May is compared to other months in Ontario:
Climate in Ontario in May
| April | May | June | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +75°F | +79°F | +86°F | ||||
| Min. temperature | ||||||
| +36°F | +43°F | +46°F | ||||
| Max. temperature | ||||||
| +97°F | +104°F | +111°F | ||||
| Rainfall | ||||||
| 27 mm | 12 mm | 2 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 62% | 64% | 62% | ||||
| Air pressure | ||||||
| 1014 HPa | 1012 HPa | 1011 HPa | ||||
| Sunny days | ||||||
| 8 | 8 | 12 | ||||
| Cloudy days | ||||||
| 15 | 19 | 17 | ||||
| Rainy days | ||||||
| 7 | 4 | 1 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
May weather is still as good as in April. It’s getting warmer as May arrives. The average maximum temperature goes up from +75°F to +79°F during the day. As May arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 27 mm to 12 mm. Humidity rises from 62% to 64%. The average wind speed doesn’t change much during May, staying around 2 m/s. The amount of sunny days stay about the same, averaging 8 sunny days during the month.
But maybe it is worth considering traveling in June as the weather gets better.
Wind
The average wind speed is 3 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Ontario is gradually increasing during May, going from 4 m/s to 5 m/s over the course of the month.
Rain
How was the weather last May in Ontario?
Climate Change Over the Years
The climate in Ontario in May 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 May a good time to visit Ontario?
Can you sunbathe in Ontario in May?
Is Ontario rainy in May?
Is it sunny in Ontario in May?
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.
