Climate in Ontario

Average daytime and nighttime temperatures

All climatic diagrams on this site result from the collected data from 33 measuring stations in Ontario.
All data correspond to the average monthly values of the last 20 years.

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Ontario is one of the warmest region in Canada with an average daily high temperature of 12 degrees centigrade. The climate is very changeable and offers varied seasons with deep winters and warm summers. It rarely gets really warm here and you can safely leave your swimwear at home. Due to the warmer temperatures the best time for traveling is from May to September. Nearly unattractive for tourists 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
Hours of sunshine per daySunshine hours per day in Ontario
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 country part Ontario. In December the sun shines the shortest.
Rainy days per monthRainy days per month in Ontario
A rainy day is a day on which at least an amount of 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 rainy days, October offers the most number of rainy days, and in March the least.
Precipitation in mm/dayPrecipitation in Ontario
The amount of precipitation is measured in millimeters per square meter. Thus, at 2 mm/day, 2 liters of water fall on one square meter within 24 hours. With only 1.5 mm, the least rain falls in January. June, on the other hand, has the most rain.
Relative humidity in %Relative humidity in Ontario
Warm air can absorb more moisture than cold air. The relative humidity indicates how much moisture of the physically possible is actually contained in the air. At high humidity, the person feels uncomfortable and perceives this as oppressive. In general, a relative humidity of 40-60% gives as 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/m³Absolute humidity in Ontario
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.
Map of Ontario

Most important cities in the country part »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 country part has a west-east extension of about 1470 km and over 990 km from north to south.

Toronto2,965,71343° 42' 0"N79° 24' 59"W
Ottawa1,028,51445° 24' 40"N75° 41' 53"W
Mississauga769,05043° 34' 44"N79° 39' 30"W
Brampton696,97543° 41' 0"N79° 45' 59"W
Hamilton574,26343° 15' 0"N79° 50' 59"W
London426,13942° 59' 0"N81° 13' 59"W
Markham343,69843° 52' 1"N79° 15' 59"W
Vaughan325,67843° 50' 10"N79° 29' 54"W
Kitchener263,79043° 25' 31"N80° 30' 40"W
Windsor234,04842° 18' 0"N83° 0' 60"W
Oakville212,55143° 27' 0"N79° 40' 59"W
Richmond Hill203,99643° 52' 16"N79° 26' 14"W
Burlington190,19443° 23' 10"N79° 50' 14"W
Oshawa175,22043° 54' 0"N78° 50' 58"W
Greater Sudbury168,14146° 29' 24"N80° 59' 24"W
Barrie149,30244° 24' 0"N79° 39' 59"W
Guelph143,16943° 32' 45"N80° 15' 22"W
St. Catharines141,29443° 10' 17"N79° 14' 34"W
Cambridge139,99643° 21' 36"N80° 18' 46"W
Kingston135,20444° 13' 47"N76° 28' 52"W
Ajax129,49043° 51' 0"N79° 1' 58"W
Milton129,33443° 31' 1"N79° 52' 59"W
Waterloo119,86943° 28' 0"N80° 30' 59"W
Thunder Bay112,74048° 22' 55"N89° 15' 1"W
Brantford104,90243° 8' 0"N80° 15' 59"W
Niagara Falls88,07143° 6' 0"N79° 3' 59"W
Pickering87,83843° 54' 0"N79° 7' 58"W
Peterborough86,46944° 18' 0"N78° 18' 58"W
Sarnia82,99842° 58' 43"N82° 24' 15"W
Willowdale79,44043° 46' 0"N79° 23' 57"W

Data basis: German Weather Service, individual values averaged and supplemented by own elements. Data on cities and inhabitants:, United Nations Statistics Division and own research.
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