United StatesAverage weather for Ontario in May
It's pleasantly warm in May in Ontario with an average temperature of 20°C. Temperatures this month range from a low of 16°C to a high of 26°C. At night, you can expect temperatures between 6°C and 15°C.
Start of May
The month of May starts in Ontario with mild temps, averaging around 18°C during the day and nights around 8°C. A few showers might pop up early in the month, but overall, it’ll stay mostly sunny and dry.
Mid May
By mid-May, daytime temps rise to around 21°C, with nights around 10°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of May
By the end of May, the average daytime temperature in Ontario is around 24°C, while nighttime temps are about 14°C. A shower might pop up, but overall, the weather will be dry and sunny.
In May, there is an average of 65 mm of precipitation, spread over 10 days. The wind speed is around 4 Bft, mostly coming from the South.
Ontario in May |
New York | ||
|---|---|---|---|
 Average temperature |
20°C | 22°C | |
 Max. temperature |
26°C | 28°C | |
| Min. temperature |
16°C | -5°C | |
 Total precipitation |
65 mm | 105 mm | |
| Rainy days |
10 days | 14 days | |
April
UV index
The UV index is a maximum of 6 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Is May a good time to visit Ontario?
Looking for great weather? May is a good time to be in Ontario. The temperatures are nice, and there’s not too much rain.
Temperature records
With 33°C in 2015, Ontario reached the highest temperature in May over the past 10 years. The lowest daytime temperature in this month was 4°C in 2020. The extreme nighttime temperatures ranged from a lowest recorded value of -3°C to a highest value of 23°C.
Check out the climate of Ontario for all months and discover the best travel time
Daily Temperature in May in Ontario
This chart shows the average daily high and low temperatures in May for Ontario, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in May in Ontario
The chart below shows the average daily precipitation in May for Ontario, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for May, you can expect about 10 days of precipitation in Ontario.
Daily UV index in May in Ontario
This chart shows the average daily UV index in May in Ontario, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in May in Ontario over the years
This chart shows the average temperature in May in Ontario, measured in degrees Celsius, over the past few years.
Total precipitation in May in Ontario over the years
This chart shows the average precipitation in May in Ontario, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily weather in May for Ontario
Click on any day in May to get detailed info about the usual weather on that day in Ontario. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in May in Ontario
Have you been to Ontario in May?
Share your weather experience in May in Ontario.
Average weather in Ontario by month
Click on a month below to see detailed weather info for Ontario. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
