An expected heat wave lasting several days so early in May could topple dozens of records across Western Canada, including on Vancouver Island, says Environment Canada meteorologist Armel Castellan.
Temperatures in the capital region are expected to peak at 28 C on Sunday and Monday and continue at 27 C through to Thursday — a five-day streak of heat that’s unusual for May.
That’s 10 to 15 degrees higher than normal for the time of year, said Castellan. “We can say it’s an extreme anomaly,” he said. “This is a big event.”
The single hottest day on record for May in Victoria was 31.6 C on May 27, 2005, following a 30C reading the day before. But to find long stretches of consecutive hot days during the month, you have to reach back a century — and even those didn’t last as long as five days.
At the Gonzales weather station in 1912, temperatures hit 28.9 on May 13 and 27.8 on May 14. In 1924, the high reached 28.3 on May 12, followed by a few days of slightly lower temperatures. The next year, in 1925 on May 16, the thermometer went to 28.9. And in 2020, starting May 9 and over three days the temperature peaked at 27.8.
Environment Canada said this time, a high-pressure ridge forming over B.C. and into the Prairies is creating a blocking pattern that has stopped normal fluctuations of low and high pressure, which means the hot air is flowing without the relief that usually comes from cooler northern air.
The stagnant blocking pattern producing the heat is sticking around, raising concerns about wildfires and flooding due to fast snowmelt, Castellan said.
“All it takes is a couple of people firing up a motorbike in the backcountry to start a forest fire,” he said.
The B.C. Wildfire Service rated the fire danger on Vancouver Island as moderate on Friday, saying forest fuels are drying and there is an increased risk of surface fires starting. There are currently no campfire bans, but that is likely to change.
Environment Canada has issued special weather statements for all of Vancouver Island — where temperatures are forecast to reach as high as 32 C in Port Alberni — as well as the rest of B.C. and Alberta.
B.C. Hydro said Friday it is expecting potentially record-breaking demand on the power system due to the increased use of fans and air conditioners.
The utility said if Monday’s forecast holds, peak hourly demand could go as high as 7,800 megawatt hours, about 1,300 more than is typical for May.
It said historically, the province hasn’t recorded anything above 7,500 megawatts in May, but its system can meet the additional demand, which is only about two-thirds of what’s typically recorded on the coldest days of the year.
The utility said its previously planned outages are being cancelled where possible to ensure customers have access to electricity to keep cool.
Dr. Shannon Waters, medical health officer for the Cowichan Valley, said the extreme heat can be dangerous for the elderly and people with medical risks and mental-health issues.
Heat exhaustion can cause dizziness, increase heart rates and lead to heat stroke, she said. People with mental illnesses can also lack the ability to recognize some of the symptoms, said Waters.
She said caregivers and family members should check in with those who are vulnerable and even consider staying the night. Although the latest heat wave isn’t as severe at the 2021 heat dome, Waters noted that some of the deaths that happened during that period happened in the night.
The City of Victoria and other municipalities usually don’t turn on misting stations or open cooling centres until an extreme heat emergency is declared by Environment Canada.
Heat warning alerts are declared by the federal agency when daytime high temperatures reach at least 29 C, and extreme heat emergencies are usually declared when heat warnings are expected to last for three or more consecutive days, with temperatures continuing to increase.
The City of Nanaimo said Friday it will turn on the taps at three city water parks Saturday — Departure Bay Kiwanis Park, Mansfield Park and Harewood Centennial Park. The Nanaimo White Rapids will be hosting an open swim on Saturday at the Kin Outdoor Pool in Bowen Park.
