Extreme heat grips much of Western Canada

A good portion of British Columbia and Alberta are under heat warnings, with temperatures expected to reach the low 40s C in some areas this weekend.

Daytime temperatures could crack the low 30s C in the Lower Mainland and eastern Vancouver Island and rise to 40 C in Interior communities like Kamloops on Sunday, according to Environment Canada — and the sweltering weather could last into the middle of the week.

"A ridge of high pressure over the region will usher in very high temperatures and will last until Thursday morning," Environment Canada said on Sunday.

Heat warnings are also in place across much of Alberta, where temperatures between 30 C and 35 C were expected during the day. Like B.C., the region could see the extreme heat last "until at least mid-week," the department said.

Misting stations were expected to be on full blast for the Calgary Stampede to cool attendees facing temperatures in the low 30s. 

The warnings extend as far north as Fort Simpson in the Northwest Territories.

Environment Canada has urged people to take precautions because of the risk to public health, and to check on their neighbours.

"Heat affects everyone, but the risks are greater for seniors, people who live alone, people with pre-existing health conditions such as diabetes, heart disease or respiratory disease, people with mental illness such as schizophrenia, depression, or anxiety, people with substance use disorders, and people with limited mobility," Environment Canada said in one of its warnings on Sunday.

Dave Ray, a meteorologist with Environment and Climate Change Canada, told CBC News on Sunday that it "does seem a lot hotter" in parts of B.C. due to recent cooler weather.

"We do have heat warnings issued fairly extensively across the South Coast and even into the southern Interior is just because going from the cool weather to all of a sudden this weather, it is a bit of a jump, a bit of a strain on people's bodies because they haven't acclimatized."

Ray said he expects temperatures to reach their highest on Vancouver Island and the South Coast on Tuesday, when Environment and Climate Change Canada estimates daytime highs in the low 30s C. He also said the current heat wave is different than the 2021 heat dome. "That was quite a significant event, not to minimize what we're going through now," Ray said.

"Something like [the current heat] you could expect to see two or three times over, say, the June-July-August stretch in any given year."

The City of Vancouver said in a news release that it has opened cooling centres in libraries and community centres, and it's reminding residents of the more than 200 permanent water fountains that are freely available for use across the city. It has also asked residents to check on vulnerable people.

"Guidance from health partners indicates that it may be unsafe for some people at greater risk of heat illness to spend time in indoor temperatures above 26 degrees Celsius," the release said. "The risk may increase significantly when indoor temperatures are above 31 degrees Celsius."