Humidex Could Hit 45°C as Heat Dome Settles Over Eastern Canada, U.S.
A massive heat dome is settling over Eastern Canada and the Eastern and Midwestern United States this week, with weathercasters warning that temperatures will hit 35°C and humidity will make it feel much warmer.
CBC says the heat warning will affect millions of people in Ontario, Quebec, New Brunswick, and Nova Scotia. The humidex—a reading that factors in the impact of humidity as well as heat—is expected to reach 40°C in Toronto, 41°C in Fredericton, and 45°C in some parts of Ontario. Ontario’s heat alert extends from Windsor as far north as Fort Albany, and from Ottawa to Sault Ste. Marie.
“Extreme heat can affect everyone’s health,” Environment and Climate Change Canada (ECCC) cautioned. “Watch for the effects of heat illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke, and the worsening of some health conditions.”
The heat could be “very oppressive,” ECCC senior meteorologist Dave Phillips told CBC. “It’s almost going to be what you see in a jungle kind of situation with the tropical nights.” He described a heat dome as a high-pressure system comparable to a convection oven, where high heat is trapped near the Earth’s surface and then pushed back down as it rises.
More than 600 people perished in the British Columbia heat dome in 2021, and poverty doubled the odds of dying.
Climate Central reports that between June 18 and 20, more than 25 million people across the eastern half of the U.S. “will experience heat made at least four times more likely because of human-caused climate change,” and the impacts are expected to continue beyond those three days.
“Human-caused climate change makes the heat season start earlier and makes heat waves hotter and more dangerous,” said Andrew Pershing, the organization’s vice president of climate science. Climate Central’s Climate Shift Index map shows local temperature projections for cities around the world.
The Climate Central release projects heat index values reaching 105°F/40.6°C in Illinois, Indiana, Michigan, Ohio, West Virginia, Pennsylvania, New York, Connecticut, and Massachusetts.
The Washington Post puts the population under heat alerts at more than 80 million, with extreme heat in the forecast for Chicago, St. Louis, Detroit, Cincinnati, Pittsburgh, New York, and Boston, among other locations. The high heat will extend into the weekend, “raising concerns regarding heat illness, especially for outdoor workers and vulnerable populations,” the Post writes.
