Authorities in Portland, Ore., said they would keep cooling shelters open through Sunday night as a likely record heat wave brought scorching weather to the normally temperate region.
At least seven people are suspected to have died of hyperthermia since the hot season began a week ago.
The most recent suspected heat-related death was announced Saturday by Clackamas County officials, Portland television station KOIN-TV reported: an elderly man who died in his home, which had no air conditioning.
The other six suspected hyperthermic deaths occurred earlier in the week in Multnomah, Umatilla and Marion counties.
Multnomah County spokeswoman Jessica Mokert-Shibley said the county, the city of Portland and other organizations would keep the cooling centers open overnight through Sunday evening. Nearly 250 people used overnight shelters Friday night, he said.
Temperatures in Portland have been nearing triple digits all week, reaching a high of 102F (38.9C) on Tuesday.
The National Weather Service issued an excessive heat advisory for both the Portland and Seattle, Wash., regions through Sunday evening, with temperatures expected to reach 103F (39C).
Shawn Weagle, a Portland-based NWS meteorologist, said Saturday that the region had likely tied its record for longest heat wave with six consecutive days topping 95F (35C). A new record could be set on Sunday, he added.
Temperatures have remained abnormally high overnight, only dropping to about 70 F (21 C), making it difficult for residents to adequately cool their homes before the sun comes up, Weagle said. Many houses in the region do not have air conditioning.
“It’s an increasingly common problem with our heat waves, the lack of recovery at night,” he said. “This really affects people who don’t have air conditioning. It’s the ‘urban island effect’: Portland’s downtown core has been built up a lot, and that concrete cools more slowly overnight than a rural valley or even a suburban neighborhood.”
The region’s heat waves also appear to be stronger overall, Weagle said.
He said he expects relief from the hot weather to arrive by midweek.
“Right now it looks like we’re going to start getting closer to normal on Tuesday, but still in the 80s, and we should be a little below normal on Wednesday,” he said.
The Seattle region was slightly cooler, but still topped 90 F (32 C) Saturday for the fifth day in a row, compared to normal temperatures in the 70s.
Weagle said people should drink plenty of water, do what they can to stay cool and keep an eye on their neighbors, especially the elderly and those at higher risk of heat-related illness.
Climate change is fueling longer heat waves in the Pacific Northwest, a region where week-long heat spells were historically rare, experts say.
Residents and officials in the Northwest have been trying to adjust to the likely reality of longer and hotter heat waves after last summer’s deadly “heat dome” weather phenomenon that drove temperatures and deaths record
About 800 people died in Oregon, Washington and British Columbia during this heat wave, which hit in late June and early July.
At the time, the temperature soared to a record high of 116 F (46.7 C) in Portland and broke heat records in cities and towns across the region. Many of those who died were older and lived alone.