June Gloom Is Gone: Expect Temps Around 90 In The Puget Sound Region; Coastal Heat Too

Jun 23, 2017

If you like heat, this is the weekend for you in the Pacific Northwest. Just in time for the official start of summer, temperatures are about to zoom all the way up to near 90 degrees.

“And I think some people will see record temperatures this weekend,” said KNKX weather expert Cliff Mass, who was quick to clarify that these would only be for a single day in question, which are "not such a big deal. “

He says the perfect weather people will see Friday won’t really last. It’s cool, clear and beautiful with the kind of clear skies that have made Seattle famous in corny old pop songs.

“A transitional day, but a perfect day,” said Mass of that weather, explaining that as high pressure builds aloft, that pushes the mercury up, warming the air.

“Temperatures though will only get to the upper 70s, maybe 80 here in Puget Sound,” he said.

Hotter Saturday – Even On The Coast

“As the easterly offshore flow moves up into the Washington Cascades, we’ll get offshore flow over our mountains, it’ll give us warming and the pressure trough moving northward, roughly over the Olympic Peninsula.”

"That will cause temperatures to warm up [Saturday] over Seattle and I expect temperatures to get to the mid-80s, maybe even 87-88 in some places away from the water. But the temperatures will be particularly warm along the Washington coast,” Mass said.

He says places such as Hoquiam and Quillayute could see temperatures in the upper 80s – so, “really toasty,” for those coastal locations that normally have the cooler marine influence.

Hottest On Sunday – Especially Inland

Mass says “things get really interesting” on Sunday as “that thermal trough” starts moving eastward over Seattle.

This means Sunday  "will be our warmest day of the weekend,” he said, predicting that temps will likely hit 92 or 93, if you’re near the water.

“If you go inland, say to North Bend or some of the eastern Suburbs, temperatures could drive way up to the mid-90s. So, it could be really warm if you get away from the water,” Mass said.

“So Sunday’s the warmest day,” he said. “Good chance there’ll be some record temperatures there – record temperatures for the date.”

But he says the coastal areas will see cooling on Sunday, as a thermal trough moves inland and the cool air pushes into places along the water.

Cooler Again For The Start Of The Workweek

“On Monday, we expect this thermal trough – this area of low pressure – to jump into Eastern Washington. So, I would expect Monday to be considerably cooler as marine air pushes into Western Washington,” Mass said.

He says temperatures will come down from the lower 90s, “probably into the lower 80s on Monday.”

“So it’ll be definitely a step down – and then a further step down on Tuesday,” Mass said. 

To hear an extended forecast, along with Mass's discussion of why the time of year that the highest yearly temperatures strike varies widely around the country (hint: more than just the solstice is a factor) you can click on the 'play' icon at the top of this post. 

Weather with Cliff Mass airs at 9:02 a.m. Friday, right after BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KNKX environment reporter Bellamy Pailthorp. Cliff Mass is a University of Washington professor of atmospheric sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to podcasts of Weather with Cliff Mass shows, via iTunes or Google Play.