PORTLAND, Ore. (AP) — An early May heat wave this weekend could surpass daily records in parts of the Pacific Northwest and worsen wildfires already burning in western Canada, a historically temperate region that has grappled with scorching summer temperatures and unprecedented wildfires fueled by climate change in recent years.
“We’re looking at record-breaking temperatures,” said Miles Higa, meteorologist at the National Weather Service’s Portland office, describing the warmth as “unusual for this time of year.”
The unseasonal high temperatures could further flame the dozens of fires burning in Canada's western Alberta province, where officials have ordered evacuations and declared a state of emergency. Residents and officials in the Northwest have been trying to adjust to the likely reality of longer, hotter heat waves following the deadly " heat dome " weather phenomenon in 2021 that prompted record temperatures and deaths across the region.
The National Weather Service issued a heat advisory Friday lasting from Saturday through Monday for much of the western parts of both Oregon and Washington state. It said the temperatures could raise the risk of heat-related illness, particularly for those who are dehydrated or don't have effective cooling.
Temperatures in Portland, Oregon, are expected to hover around 94 F (34.4 C) throughout the weekend, according to the website of the National Weather Service office there. The current daily temperature records for May 13 and 14 stand at 92 F (33.3 C) and 91 F (32.8 C), dating from 1973 and 2014, respectively.
Elizabeth Romero and her three children were among those cooling off at a fountain in downtown Portland on Friday afternoon.
“We decided to stop by ... until we all feel better," she said, adding that she plans to seek out shaded parks during the weekend.
Temperatures in the Seattle area could also meet or surpass daily records, according to National Weather Service meteorologist Jacob DeFlitch. The mercury could near 85 F (29.4 C) on Saturday and reach into the low 90s (32.2 C) on Sunday, he said.
King County, home to Seattle, directed transportation operators such as bus drivers to let people ride for free if they're seeking respite from the heat or heading to a cooling center. The county's regional homeless authority said several cooling and day centers will be open across the county.
Authorities also urged people to be wary of cold water temperatures, should they be tempted to take a river or lake swim to cool off.
“Rivers are still running cold. We have snow melting and temperatures … probably in the low- to mid-40s (4.4 to 7.2 C) right now,” National Weather Service meteorologist Higa said. “You’re nice and warm and jump into the cold water — that could pose a risk to getting cold water shock.”
Residents and officials in the Pacific Northwest have become more vigilant about heat wave preparations after some 800 people died in Oregon, Washington and British Columbia during the heat dome weather event in late June and early July 2021. The temperature at the time soared to an all-time high of 116 F (46.7 C) in Portland and smashed heat records in cities and towns across the region. Many of those who died were older people who lived alone.
In response, Oregon passed a law requiring all new housing built after April 2024 to have air conditioning installed in at least one room. The law already prohibits landlords in most cases from restricting tenants from installing cooling devices in their rental units.
Last summer, Portland launched a heat response program with the goal of installing portable heat pump and cooling units in low-income households, prioritizing residents who are older and live alone, as well as those with underlying health conditions. Local nonprofits participating in the program installed more than 3,000 units last year, according to the city's Bureau of Planning and Sustainability.
One of those nonprofits, Verde, said interest in the units has been high. Verde has installed roughly 180 units so far this year, and their waitlist last year was nearly 500 people long, said Ricardo Moreno, a project manager for the group who oversees its heat response program.
“People we’ve talked to, mostly elderly people with some health conditions, they all shared that having these units have made a world of difference and definitely improved the quality of their lives through the summer,” Moreno said.
Another local nonprofit, the African American Alliance for Homeownership, installed 1,200 units last year and 75 units so far this year, program manager Richard Hines-Norwood said.
Officials in Multnomah County, home to Portland, said they weren’t planning on opening special cooling centers for now but are monitoring the forecast and can do so if needed.
“This is the first significant event … and it is early for us,” said Chris Voss, the county’s director of emergency management. “We’re not seeing a situation where we are hearing that this is extremely dangerous. That being said, we don’t know if it’s going to drift.”
Outreach teams have started visiting homeless encampments to let them know about the resources available to them, Voss said. Air-conditioned libraries are an example of a public place where people can cool off, he added.
Associated Press writer Ed Komenda contributed from Seattle.
Claire Rush is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on undercovered issues.