'Notable' heatwave expected in B.C. by next weekend: ECCC

A bright hot sun in the sky. (File photo/CTV News)

British Columbians should begin bracing for a stretch of hot weather starting late this week, with temperatures expected to climb up to 10 C above seasonal averages, according to a meteorologist with Environment Canada.

Chris Doyle, with the weather agency, says the incoming heat wave is expected to start Friday and to persist into the following week.

"It's notable because it's going to be a long period of elevated temperatures," he tells CTV News. "We are going to be in a bonafide long-term warm period."

In terms of just how hot it's going to get, the forecast varies by region. Daytime temperatures are expected to be between four and eight degrees above average on the South Coast, meaning temperatures will range from the mid-20s C to around 30 C. In the Interior, daytime temperatures between five and 10 degrees above average could mean highs of up to 40 C by early next week.

One of the concerns about the duration of this heat wave is the impact it will have on overnight temperatures, which are also expected to be above average.

"As these warm days successively pass one after the other, even the water temperature of the Georgia Strait goes up -- that's our coastal refrigerator," Doyle explains. "Once those water temperatures start to go up, it starts to get a little more humid. So the longer this thing goes on, the more muggy it's going to get, and the less overnight recovery we can expect."

The agency has not yet issued any warnings, but that doesn't mean none are forthcoming.

"We're poring over the models, we're trying to decide at what point those temperature thresholds will meet the requirements for a heat warning," Doyle said. "We don't want to put something out too early, because people often think it's in effect right away."

Still, Doyle said, it's not too early for people to start thinking about how to prepare to support those who are most vulnerable to the impacts of extreme heat. While conditions are not expected to approach those of 2021's deadly heat dome, Doyle says it's still important to heed the lessons learned from the mass casulaty event about who is most vulnerable to extreme heat – including the elderly, people who live alone, disabled people and people who live in poorer, denser urban areas in housing that is not equipped with adequate cooling.