Seattle is going to be so hot over the next couple of days that when temperatures drop to 90 degrees Tuesday, it will come as a relief.
On Monday, Seattle could reach 104 degrees, according to the National Weather Service. Saturday and Sunday are expected to reach 97 and 102 degrees respectively, and heat records are likely to be broken throughout the Puget Sound.
The extreme heat prompted Gov. Jay Inslee on Friday to lift COVID-19 capacity restrictions on nonprofit or publicly owned or operated cooling centers.
“Beginning today, and persisting well into next week, meteorologists predict that temperatures will rise rapidly throughout the Pacific Northwest,” Inslee said in a statement. “Consequently, Washingtonians will be at high to very high risk of heat-related effects. In response, many local governments are mobilizing ‘cooling centers’ to protect people from the weather. I want to ensure that local jurisdictions have flexibility in options that can provide relief from the heat.”
Around the state, other preparations were underway. Some vaccination clinics closed, including three in Kitsap County.
The Seattle Department of Transportation announced it would be halting traffic on the city’s steel-decked bridges to spray them down with water. Thermal expansion could otherwise increase the deck size, inhibiting drawspans from opening and closing correctly, SDOT said.
The so-called heat dome — a heat wave that sits over one region — has stretched across the western United States for nearly two weeks, setting record temperatures from Omaha to Death Valley.
The region’s utilities are coordinating to handle a surge in energy and water use that is expected over the coming days.
Seattle City Light is expecting a 20% jump in electricity use on Monday above what is typical for this time of year. Utility officials say there are enough resources to manage the expected load increases during the heat wave. Seattle Public Utilities also said there’s no cause for concern about the region’s water supply.
One longstanding record broken was in Salt Lake City, where the mercury rose to 102 degrees, breaking the record for that date, 100, set in 1918. June 13, 2021, is also the earliest instance of a 102-degree temperature in Salt Lake City, breaking the previous record from June 15, 1974, according to the weather service.
The intense heat has prompted the National Weather Service to issue excessive heat watches and warnings throughout the West, including in Washington.
Researchers say Seattle and other areas of the Pacific Northwest are poorly adapted to extreme heat. Residents are not physically acclimated to heat, and fewer than half have home air conditioning, one of the lowest rates among big U.S. cities. But, Seattle is becoming a lot more air-conditioned than it used to be.
Also, nighttime temperatures, which often provided a respite on hot Seattle days, will be less reliably comfortable. In the Northwest, overnight low temperatures are actually warming more rapidly than are daytime temperatures.
The all-time warmest overnight low temperature until now was 71 degrees, set July 29, 2009, but that’s another record likely to be broken as forecasters predict lows of 70 degrees on Saturday night and 73 on Sunday.
In the Puget Sound region, average minimum temperatures have climbed between 3 and 4 degrees, Washington’s state climatologist Nick Bond said.
Justin Pullin, with the National Weather Service in Seattle, said the high pressure system will be in the region through the July 4 weekend, but temperatures will drop slightly to 90 degrees on Tuesday, and then remain in the 80s through the holiday.
Seattle Times staff reporters Daniel Beekman and Joe O’Sullivan contributed to this story.