Pacific Northwest braces for extreme heat, threat of fires

WASHINGTON — After an extreme early-season heat wave in May, the Pacific Northwest largely avoided the relentless heat that has plagued the southern United States this summer. That changed Sunday, though, as intense heat arrived in portions of Oregon and Washington state that is expected to last through much of the week, this time coinciding with the hottest time of the year.

Heat alerts cover all of Oregon and Washington and extend into northern and interior sections of California, as well. British Columbia’s South Coast is also under a heat warning. This week’s heat could rival last year’s week of blistering heat in the Pacific Northwest in late July and early August, but shouldn’t be as intense as the unprecedented, record-smashing heat wave of June 2021.

The interior valleys and lower elevations of western Oregon could have one of their hottest five-day stretches on record, the National Weather Service said, including Portland, Salem, Eugene and Medford. In Washington, the heat could come close to or break record highs during the next few days in Seattle, Spokane, Olympia, Yakima, Omak and Kennewick.

The humidity won’t be nearly as high as in the southern United States, where locations including New Orleans, Houston and Austin continue to dominate the hottest cities listed on The Washington Post’s heat tracker, but the heat will be dangerous nonetheless.

“Now is the time to begin to put your heat plans into action,” the National Weather Service said. “This is particularly true for anyone without reliable access to cooled and air conditioned locations, and anyone with plans for outdoor recreation. Have a way to limit your heat exposure and stay hydrated!”

In addition to its effects on people’s health and comfort, the heat will also elevate the fire threat in much of the region. Red-flag warnings for high fire danger are in effect for much of western Washington and Oregon. Evacuations were ordered late Sunday for the Lookout Fire east of Eugene, Ore.

Temperatures soared into the triple digits Sunday in northwest Oregon, including in Troutdale, where the high of 105 degrees Fahrenheit broke the record for the date of 104 from 2002. Hillsboro tied its daily record high of 101. Portland’s high of 101 was one degree shy of a record, while Medford’s high of 106 fell two degrees short.

Several cities in Oregon including Portland, Salem, Eugene, Hillsboro and McMinnville could break their record highs on Monday by five degrees or more, according to weather historian Don Sutherland, and some locations could challenge their all-time highs for August:

Salem is forecast to reach a high of 107 on Monday, which would crush the record high of 102 from 1942, falling just one degree short of the alltime August high of 108. High temperatures are expected to remain at or above 100 through Wednesday before a late-week cooling trend.

Eugene’s forecast high of 105 on Monday would easily top the record high of 101 in 2010, but would fall short of the all-time August record of 108. High temperatures are forecast near 100 today and Wednesday before gradually cooling late this week and weekend.

Portland is forecast to reach a high near 104 on Monday, which would break the record high of 102 from 2008, but fall short of the alltime August high of 107. High temperatures are expected to remain near or above 100 through Wednesday before cooling later in the week.

With forecast highs on Monday of 104 and 107, respectively, Hillsboro and McMinnville are both likely to break their daily record highs. and could come within a degree or two of their all-time August high temperatures.

The heat won’t be terribly unusual for Medford, but it will be persistent with forecast highs of 104 to 110 degrees expected to tie or break the record high every day through Thursday.

The heat is on in Washington state as well, with Yakima, Omak and Kennewick expecting highs around 102 to 108 through midweek. In Yakima, the forecast of high of 107 today would break the daily record high of 103 from 2021. Likewise, the forecast high of 108 today for Kennewick would break the daily record high of 104 in 2021. Seattle won’t be as hot, but could come close to its daily record high of 91 on Monday, with forecast highs near 90 through Wednesday.