Heat wave and widespread warnings hit Ontario

Most of Ontario started to swelter on Monday as what's expected to be a prolonged heat wave arrived in the province, with Environment Canada warning that many communities could experience dangerously high temperatures this week.

The weather agency issued heat warnings for large swathes of the province, from southwestern Ontario all the way to the Quebec border, stretching up to Sault Ste. Marie and as far north as Moosonee. It warned that vulnerable people would be particularly at risk as temperatures soar.

Temperatures in the Greater Toronto Area and Ottawa could feel as hot as 45 C with the humidity this week. Regions further north are also forecast to see humidex values that could feel like the low to mid 40s.

"It's certainly out of the norm," Environment Canada meteorologist Gerald Cheng said in a phone interview Monday.

"Normally we should be at 25 C for daytime highs and 14 C for nighttime lows."

A weather system south of the border is driving the heat, Cheng said, with hot air expected to later move eastward, blanketing much of southern Quebec and most of New Brunswick later this week.

"The air mass from the south is importing hot and humid weather into Ontario and that's why we're looking at temperatures into the 30s and humidex values into the 40s," Cheng said.

Factors at play during the heat wave include normal weather fluctuations that can sometimes lead to temperature spikes as early as May, Cheng said, and the ongoing effects of global warming.

"Climate change is working in the background to make these heat events more likely and more intense in the long run," he said.

This week's heat wave was made twice as likely by climate change, Climate Central, a U.S.-based non-profit group of scientists and communicators, wrote in a statement. The U.S. National Weather Service has also issued warnings about record-breaking heat expected from the Midwest to the Northeast over the next several days.

The health risks associated with heat are greater for older adults, infants and young children and other vulnerable groups, Environment Canada said.

It's important to stay hydrated, avoid physical activities during the height of day, and follow the advice of public health experts, Cheng said. He also urged people to check in on their neighbours, especially if they are elderly or otherwise vulnerable.

In downtown Toronto, Bob Brooks was sitting under a tree to take a break from the sun.

"I just limit the amount of exposure to the sun and sit in the shade and use a fan and I'm fine," he said, adding that he had adapted to hot weather after years of living in Bangkok, Thailand.

The Toronto District School Board said in a note to parents that it’s expecting “uncomfortable conditions” this week in schools that are only partially air-conditioned or have no A/C at all. It said staff will be using fans, turning lights off, closing curtains and keeping windows open when possible.

The school board said parents should encourage children to wear light clothing and drink lots of water, while noting that heat-wave-related school closures are not typical.

The City of Toronto said people experiencing homelessness can seek reprieve from the heat at various drop-in centres, shelters and 24-hour respite sites across the city.

Street outreach programs are also dispatching teams to conduct wellness checks, provide water and encourage unhoused people to go to a cool space, city spokesperson Elise von Scheel wrote in an email.

The city's Heat Relief Network lists hundreds of locations across Toronto that provide air conditioning and other forms of respite from the heat.

But one advocate said most of those spaces are "unwelcoming" to unhoused people and the existing street outreach services "aren't reaching most people."

"There are an increasing number of people living outdoors, and they are now dispersed across the city," social worker and harm-reduction advocate Diana Chan McNally wrote in an email. "Many people don't have access to running water, either because drinking fountains and park washrooms aren't functioning, which is a running issue in Toronto, or they simply don't exist where people are living."

She said the city should bring back 24/7 emergency cooling centres, which used to welcome unhoused people as well as seniors and tenants of apartment buildings without air conditioning.

A spokesperson for the Ontario Ministry of Long-Term Care said all nursing homes in the province, except for two that are being redeveloped, are "fully air-conditioned."

Meanwhile, the province's Independent Electricity System Operator said Monday there will be enough electricity supply to meet the additional demand created by the heat wave.

Parts of southern and central Quebec are also bracing for extreme temperatures of between 30 and 35 C, with a humidex of over 40 C, according to Environment Canada meteorologist Jean-Philippe Bégin.

“What differentiates this heat wave versus others that we had in the past is the intensity,” and especially the humidity, he said, adding that it's "going to feel tropical."

A spokesman for the City of Montreal said each borough was creating a list of places for people to cool down, including some pools that are opening earlier than planned.

For those who don't welcome the heat or struggle with it, Cheng said preparation and risk awareness will be key for the next few months.

“I think we have to remember that there is still a whole summer ahead of us," he said.

– With files from Allison Jones, Liam Casey and Morgan Lowrie.

This report by The Canadian Press was first published June 17, 2024.