Toronto, Montreal among the deadliest cities for Canadian heatwaves, federal research suggests

Toronto and Montreal rank among the deadliest cities for Canadian heat waves, according to a new longitudinal review by Statistics Canada.

Toronto and Montreal rank among the deadliest cities for Canadian heat waves, according to new research by Statistics Canada (StatCan).

Released Wednesday, the 20-year data review compared mortality rates during extreme heat events among the 12 most populous Canadian cities. Researchers found that while extreme heat is a common contributor to excess deaths in national totals, the country's two biggest cities have seen the largest spikes.

StatCan counted roughly 700 excess deaths attributed to heat between 2000 and 2020, with 230 attributed specifically to heart or lung problems.

Of the total, an estimated 250 were counted among Toronto residents and 295 in Montreal, the latter municipality known as particularly vulnerable to environmental and heat-related deaths, research shows.

"One explanation … may be the concentration of rental housing and lower levels of air conditioning access among renters, compared with owners," the study reads.

Quebec City, Ottawa, Surrey, B.C., Vancouver, Brampton, Ont. and Mississauga, Ont. saw lesser effects on excess mortality that Toronto and Montreal, ranging between 22 and 34 excess deaths in the timeframe of the review. In Calgary, Winnipeg, Edmonton and Hamilton, mortality figures during recognized extreme heat events were actually slightly lower than the baseline.