Climate in Ontario
(Canada)
Average daytime and nighttime temperatures
All climate diagrams on this site result from the collected data from 33 measuring weather stations in Ontario.
All data correspond to the average monthly values of the last 20 years.
Back to overview: Canada
Ontario is one of the warmest regions in Canada with an average daily high temperature of 12 degrees. The climate is varied and offers seasons with strong winters and warm summers. It rarely gets really warm up here. Due to the warmer temperatures, the best time for traveling is from May to September. Less attractive are the cold months from November to March.
› Overview: Climate in Canada
› Daylengths and sun positions in Canada
› Compare climate with other regions or countries
› Daylengths and sun positions in Canada
› Compare climate with other regions or countries
Sunshine hours per day
The number of hours of sunshine refers to the time when the sun is actually visible. That is, without any obstruction of visibility by clouds, fog or mountains. With 11 hours per day, July is the sunniest month in the region of Ontario. In December, the sun shines the least.
Rain days per month
A rain day is a day on which at least 0.1 mm precipitation (=0.1 liter) per square meter falls. This can be rain, snow, hail or even dew. So it does not have to rain the whole day. With 11 rain days, October offers the most rain days, while March has the fewest.
Precipitation amount in mm/day
The amount of precipitation is measured in millimeters per square meter. Thus, at two mm/day, two liters of water fall on one square meter within 24 hours. With only 1.5 mm, the least amount of rain falls in January. June, on the other hand, has the most rain.
Relative humidity in %
Warm air can absorb more moisture than cold air. The relative humidity indicates how much moisture can be physically contained in the air. At high humidity, a person feels uncomfortable and perceives this as oppressive. In general, a relative humidity of 40-60% feels pleasant. With only 63% humidity on average, it is quite dry in May. The highest value of 77% is experienced here in December.
Absolute humidity in g/m³
In warm months, there is also a higher absolute humidity almost everywhere. At a temperature of 25°C, air can absorb up to 23 grams of water per cubic meter. At 20°C, it is only 17.3 grams. A relative humidity of 40% at 25°C thus corresponds to an absolute humidity of 9.2 grams of water. From a proportion of approx. 13.5 grams, humans perceive the air as muggy.
Climate charts for other regions in Canada

Most important cities in the region »Ontario«
As the capital region, it is arguably the most important part of Canada. Alone 5 major cities with over 500,000 inhabitants are located here. The region has a west-east extension of about 1470 km and over 990 km from north to south.City | Population | Geo position | |
---|---|---|---|
Toronto | 2,974,293 | 43° 42' 0"N | 79° 24' 59"W |
Ottawa | 1,054,800 | 45° 24' 40"N | 75° 41' 53"W |
Mississauga | 769,303 | 43° 34' 44"N | 79° 39' 30"W |
Brampton | 721,237 | 43° 41' 0"N | 79° 45' 59"W |
Hamilton | 587,192 | 43° 15' 0"N | 79° 50' 59"W |
London | 434,099 | 42° 59' 0"N | 81° 13' 59"W |
Markham | 348,443 | 43° 52' 1"N | 79° 15' 59"W |
Vaughan | 333,692 | 43° 50' 10"N | 79° 29' 54"W |
Kitchener | 270,475 | 43° 25' 31"N | 80° 30' 40"W |
Windsor | 230,329 | 42° 18' 0"N | 83° 0' 60"W |
Oakville | 221,484 | 43° 27' 0"N | 79° 40' 59"W |
Richmond Hill | 209,295 | 43° 52' 16"N | 79° 26' 14"W |
Burlington | 193,533 | 43° 23' 10"N | 79° 50' 14"W |
Oshawa | 181,440 | 43° 54' 0"N | 78° 50' 58"W |
Greater Sudbury | 169,079 | 46° 29' 24"N | 80° 59' 24"W |
Barrie | 153,169 | 44° 24' 0"N | 79° 39' 59"W |
Guelph | 146,600 | 43° 32' 45"N | 80° 15' 22"W |
Cambridge | 143,245 | 43° 21' 36"N | 80° 18' 46"W |
St. Catharines | 141,397 | 43° 10' 17"N | 79° 14' 34"W |
Milton | 138,495 | 43° 31' 1"N | 79° 52' 59"W |
Kingston | 135,169 | 44° 13' 47"N | 76° 28' 52"W |
Ajax | 134,450 | 43° 51' 0"N | 79° 1' 58"W |
Waterloo | 123,991 | 43° 28' 0"N | 80° 30' 59"W |
Thunder Bay | 110,790 | 48° 22' 55"N | 89° 15' 1"W |
Brantford | 107,985 | 43° 8' 0"N | 80° 15' 59"W |
Niagara Falls | 88,071 | 43° 6' 0"N | 79° 3' 59"W |
Pickering | 87,838 | 43° 54' 0"N | 79° 7' 58"W |
Peterborough | 85,456 | 44° 18' 0"N | 78° 18' 58"W |
Sarnia | 82,998 | 42° 58' 43"N | 82° 24' 15"W |
Willowdale | 79,440 | 43° 46' 0"N | 79° 23' 57"W |
Data basis: German Weather Service, individual values averaged and supplemented by own elements. Data on cities and inhabitants: geonames.org, United Nations Statistics Division and own research.