Hazardous heat comes to the Pacific Northwest

Potentially hazardous heat that could break daily records, with high temperatures in the 90s or even triple digits, is expected in the Pacific Northwest starting Sunday, according to the National Weather Service (NWS).

Driving the news: An upper-level ridge of high pressure over western Washington and Oregon will likely continue to bring temperatures near or over 100 to the Portland and Vancouver area for the next several days, National Weather Service meteorologist Steve Reedy told Axios.

• Overnight temperatures that could remain near 65 in the Puget Sound region and as high as 72 in southwest Washington and western Oregon raise further health concerns, said Reedy.
• The heat in Seattle will persist through Wednesday or Thursday.
• In Oregon, the heat may last through Friday and forecasters are warning of major heat risk, Noah Alviz of NWS Portland told Axios.

The ridge should begin to break down by next weekend, said Reedy, with temperatures cooling slightly into the 80s throughout the region.

The big picture: The Pacific Northwest stood out this year for its relatively mild temperatures compared to the widespread heat waves blanketing the U.S. for much of this summer, and the world's record-breaking July temperatures.

• The worldwide extreme heat would have been "virtually impossible" without human-caused climate change and greenhouse gas emissions, according to a recent study.
• Last year, Seattle had multiple 90-degree days in a row and in June 2021 had an unprecedented heat wave.
• Meanwhile, Portland recorded its seventh warmest year ever last year and broke records in October for the longest stretch of 80-plus degree days. It recorded its all-time highest temperature of 116 degrees in June 2021.

What they're saying: "It's a little sad that 20 years ago, three to four days of 90 degree weather would be eye-popping," Justin Shaw of the Seattle Weather Blog told Axios. "Now it's almost commonplace."

• "This heat event will affect anyone without effective cooling or adequate hydration," Alviz said.

NWS Portland is urging people to drink plenty of water, spend time in air-conditioned spaces, wear light-colored clothing and stay out of the afternoon sun.

• Most importantly, Alviz said, check on each other, especially children and elderly people.
• "No one should be alone in a heat wave," he said.