‘Heat dome’ may push Western Washington temperatures into record-breaking territory

The ‘heat dome’ is here.

Possible record-breaking temperatures may hit the state Monday as a widespread ridge of high pressure and accompanying high temperatures scorch the West and hover over Washington before heading east Tuesday.

The so-called heat dome, which has stretched across the Western United States for the past week and is now creeping north and east, has set record temperatures from Omaha to Death Valley. The heat dome is a heat wave that sits over one region — in this case, the entire Western half of the United States — and stays there, said Mary Butwin, meteorologist at the National Weather Service in Seattle.

In Seattle, Sunday’s high was in the low-80s, she said.

Monday may be the hottest day of the year so far, with temperatures jumping to the high 80s and low 90s, she said, depending on where in the metro area you live. In South King County, Monday’s temperature could break the June 21 record logged at Seattle-Tacoma International Airport, of 89 degrees in 1992. The all-time high for June at the airport was 96 degrees on June 25, 2017.

There’s “good potential” for breaking the record, Butwin said. “It’s going to be close.”

Vancouver and other southern Washington cities could see temperatures sizzle into the mid-90s on Monday, Butwin said. Spokane is forecast to reach 91 degrees. But, Butwin said, it’s “probably going to be warmer.”

Temperatures are expected to drop to the upper 70s on Tuesday with the return of cool marine air. But another warm front is expected by Friday: Temperatures in the mid to upper 80s are on their way, with even warmer weather predicted by next weekend, Butwin said. “It is warmer than normal, for June at least … but it’s not unheard of.”

Despite a rainy stretch last weekend, Western Washington has had a spell of dry weather, raising the risk of wildfire, Butwin said. But the weather service has not yet issued a red-flag warning, which signals a high likelihood that fire could start or spread.

Officials warn that while the air may be warm, Washington’s waters are still cold. So swimmers and other water enthusiasts should take precautions to prevent cold shock, which is a sudden and involuntary onset of gasping and muscle failure that can happen when someone is exposed to cold water.