The extraordinary heat wave that's stifling the Pacific Northwest will peak in many areas on Monday, with Seattle having smashed its all-time high-temperature record, set just the day before, by at least 2°F.
Why it matters: After two days of oppressive heat and little relief at night, the extreme weather event, boosted by global warming, is moving into a more dangerous phase.
- Heat illness tends to spike the longer heat waves last, and extreme heat is the No. 1 weather-related killer each year in the U.S.
Driving the news: A highly unusual weather pattern that statistically has less than a 1-in-several-thousand-year chance of occurring is in place over the Pacific Northwest, with a record-strong high-pressure area aloft — colloquially known as a "heat dome" — sitting over Washington state and British Columbia.
- This heat dome is yielding temperatures 25–50°F above average across multiple states and British Columbia.
- This heat, combined with a worsening drought, is raising the risk of wildfires across multiple Western states, with some large blazes erupting in California Sunday and Monday.
- It is also causing power demand to spike at a time when hydropower resources are lower than usual.
By the numbers: All of Oregon, Washington and Idaho, plus portions of California, Montana and Nevada, are under excessive heat watches and warnings....
- Portland, Oregon, set an all-time high temperature of 112°F on Sunday, and eclipsed that on Monday, with a high of 115°F so far.
- In Seattle, the temperature reached 104°F on Sunday, which broke the existing all-time record. It exceeded this on Monday, standing at 106°F