While the weather might currently be cool, it was only five years ago that B.C. underwent an unprecedented, deadly heat dome.
From June 25 to July 1, 2021, B.C. experienced temperatures it had never seen before, with the hottest day on June 28.
Pitt Meadows hit 41.4°C, Vancouver International 31.7°C, West Vancouver 39.2ºC, and White Rock 38.5ºC. In Lytton, the temperature hit an all-time Canadian temperature record of 49.6ºC. Nighttime temperatures remained high throughout.
The heat dome resulted in 619 deaths across B.C., making it the deadliest weather event in its history. According to scientists from the World Weather Attribution, it would have been “virtually impossible without human-caused climate change.”
B.C. was not ready for such an event because it had never experienced anything like it before, said Andréanne Doyon, a professor at SFU in the School of Resource and Environmental Management.
“It’s not like we haven’t had heat events in the past, but 2021 was a record-setting heat event,” she said.
B.C. also had heat waves the following two summers of 2022 and 2023, showing that 2021 wasn’t a “complete fluke.”
“It changed the conversation in terms of how we talk about heat, in the fact that we now talk about heat,” said Doyon.
Why weren’t cities prepared for the 2021 heat dome?
Not only was heat not on anyone’s radar prior to 2021, but Doyon said that B.C. municipalities and the province have a lack of expertise on it — they don’t have people trained in handling and preparing for extreme temperatures.
“Most people, the first time they lived through an extreme heat event would have been 2021. So we have the ‘We’ve never experienced this,’ which means we’ve never talked about it. And then we have the ‘I actually don’t know what to do.'”
Instead, people in the Lower Mainland tend to be skilled around stormwater management, since “we’ve always dealt with water.”
Further, most buildings in B.C. were built according to the climate at the time, without future climate projections in mind.
For example, B.C. homes have some of the lowest rates of air conditioning in the country, which Doyon said is partly because the building code didn’t used to require buildings to stay cool.
Buildings also weren’t constructed in ways to keep them cool. Doyon pointed out the glass downtown towers where you can’t open windows.
“And you’re kind of going, ‘What?’ But those buildings were built to those current standards,” she said.
What’s been done since 2021?
After the heat dome, the B.C. government updated some of these standards, changing the B.C. Building Code to ensure that all new residential buildings must provide one living space with a temperature that doesn’t exceed 26°C, either through passive design measures or with cooling equipment.
In a statement that B.C.’s provincial health officer, Bonnie Henry, sent out to the media, she said the province made a “commitment to learn as much as we could about who and how people were affected.” Since 2021, they have developed the B.C. Heat Alert and Response System and the Extreme Heat Preparedness Guide.
“These resources help people at every level, from personal to community to provincial, to be aware and to plan for heat events,” Henry said.
And at a municipal level, Doyon said that Vancouver and New Westminster have been leaders in the region.
For example, Vancouver has conducted its Indoor HEAT Study to understand how hot it actually gets inside homes and how it affects people.
Meanwhile, New Westminster recently passed a bylaw requiring landlords and property owners to keep their rentals from reaching dangerous temperatures. They now require at least one living space in an occupied rental unit to be maintained at or below 26°C between 8 p.m. and 8 a.m., from April 1 to Oct. 31.
Doyon acknowledged that this bylaw isn’t necessarily realistic. Some older buildings can’t handle the power load if everyone had AC. Further, the City hasn’t promised to provide landlords with the funding to meet the new regulations.
“But it’s making a statement, right, this is important,” she said.
It also allows for some form of accountability. For example, if another extreme heat event happens and there’s a high death rate in a certain building, the bylaw would help keep the building owner or manager accountable in some way.
Further, if people feel unsafe in their apartments due to the heat, they now have something tangible they can point to.
What should people do during heat events?
Doyon said another thing that cities have done is provide resources to people, teaching them how they can keep their homes cool and safe.
“Something that surprised me during the heat dome was how little people knew — people were keeping their curtains open and keeping their windows open,” said Doyon.
During hot weather, she said people should keep windows and curtains shut during the day, since leaving them open invites the sun in to heat up the space.
On the City of Vancouver’s website, it advises people to use a thermometer to measure temperatures, since temperatures above 26°C can be dangerous for vulnerable populations. If it is 31°C or higher, the City suggests leaving and going to a cool space.
It also tells people to use an air conditioner to cool their home (and to host people who don’t have an AC), open windows and doors when the outdoor temperature is lower than the indoor temperature, wear a wet shawl, cloth, or shirt, and drink plenty of water before you feel thirsty.
Many Lower Mainland cities also offer cooling spaces for residents to visit during heat events.
“What cities are trying to do is offer more spaces for people to go during these times, and they’re trying to sort of remind people that these spaces exist,” said Doyon.
She said these are useful during the day, but not at night when you need a space to sleep. They also pose an issue if someone has mobility issues and challenges accessing them.
But what about the “big level” changes?
Doyon said that many neighbourhoods in the Lower Mainland need “big level change.”
For some, this could look like more green space and urban tree canopy, which is known to reduce temperatures.
“For Vancouver, we know the neighborhoods that were the hottest were not only the most sort of lower socioeconomic, but they also were the ones with less vegetation,” Doyon said.
But what might be even more important are retrofits to help keep buildings cool.
Retrofits include things like installing higher quality windows, sealing around windows and doors to prevent drafts, better insulation, shade structures added to the outside of buildings and mechanical cooling like a heat pump or an air conditioning unit.
“The challenge there is who’s going to pay for it,” she said.
Doyon said that decisions about how we build future homes need to incorporate heat as a factor — things like the colour, material, and orientation of buildings, as well as adding shade structures on them. Further, she said we need to think about building in places that are less prone to heating up, as certain locations are hotter than others.
But she stressed that senior levels of government need to step up, as there’s only so much authority and funding that municipal governments have.
“Five years later, where are we at? Well, this needs to be prioritized, and there needs to be money to do the work.”