Hottest Canadian Cities in Summer

Two far-flung Canadian cities contend for the title of the hottest large city in Canada. Windsor, Ontario and Kelowna, British Columbia are neck and neck for highest average daily maximum temperature, with Windsor leading by only 0.2 degrees Celsius (0.4 degrees Fahrenheit).

But Kelowna outshines Windsor when it comes to extreme heat. The BC city leads the rankings for most days with temperatures of 30 degrees Celsius (86 °F) or above at 24 days. Windsor comes in second, having four days fewer than Kelowna.

With these results, Kelowna could understandably be considered the country's hottest summer city. But this city of hot days can't keep the heat up at night. Kelowna doesn't even make the top ten list of Canadian cities with the warmest summer nights. Leading that list is Toronto, followed closely by Windsor. Kelowna sits far down that list at spot number 17. Its daily minimum temperature for summer averages a cool 12.6 °C (55 °F).

Besides Windsor, cities that rank in the top ten for all three hot city criteria are Brantford, Hamilton, Ottawa, St. Catharines and Toronto, all in Ontario. Among this group, Hamilton places highest for summer heat.

The tables below rank the major Canadian cities with the highest maximum and minimum temperature averages for summer and with the greatest number of really hot summertime days.

The cities included in these rankings are Canada's largest metropolitan areas. These are the 33 urban regions that had over 100,000 people according to the 2011 census by Statistics Canada. The temperature data are averages of weather measurements made from 1981 to 2010.

Hottest Summer Weather

The ten cities in Canada with the hottest summer days all have a daily high temperature that averages 25 degrees Celsius (77 ° Fahrenheit) or more.

Average daily maximum temperature in June, July and August
City High °F High °C
Windsor, Ontario 80 26.9
Kelowna, British Columbia 80 26.7
Brantford, Ontario 79 25.9
Hamilton, Ontario 79 25.8
St. Catharines, Ontario 78 25.8
Ottawa, Ontario 78 25.3
Toronto, Ontario 78 25.3
London, Ontario 77 25.3
Montréal, Quebec 77 25.1
Barrie, Ontario 77 25.0

Cities in Canada with the warmest summer nights have average low temperatures that range from 14 to nearly 17 °C.

Average daily minimum temperature in June, July and August
City Low °F Low °C
Toronto, Ontario 62 16.8
Windsor, Ontario 62 16.7
Hamilton, Ontario 60 15.3
St. Catharines, Ontario 59 15.2
Oshawa, Ontario 59 14.8
Montréal, Quebec 58 14.7
Ottawa, Ontario 58 14.5
Kingston, Ontario 58 14.4
Brantford, Ontario 58 14.2
Peterborough, Ontario 57 14.1
Barrie, Ontario 57 14.0

Most Extremely Hot Days

Heat waves with temperatures of 30 °C or more last for at least ten days a summer at Canada's ten cities with the most extreme heat. Some of these cities are even likely to feel temperatures above the mid 30s for one or two days.

Average number of days in June, July and August when the temperature rises to 30 °C (86 °F) and 35 °C (95 °F) or higher
City Days 30+ °C Days 35+ °C
Kelowna, British Columbia 24 2
Windsor, Ontario 20 1
Hamilton, Ontario 16 1
Regina, Saskatchewan 14 1
St. Catharines, Ontario 13 0
Saskatoon, Saskatchewan 12 2
Brantford, Ontario 11 0
Winnipeg, Manitoba 11 1
Ottawa - Gatineau, Ontario 11 0
Toronto, Ontario 11 1

Environment Canada. Meteorological Service of Canada. Canadian Climate Normals. 1981-2010 Climate Normals & Averages.

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