Seattle’s record-breaking heat wave sticking around through Tuesday

The hot weather is going to stick around through Tuesday before temperatures start to ease later this week.

On Sunday, a few daily records for high temperatures were set. The Seattle-Tacoma International Airport (SEA) eclipsed the previous record of 90 set in 2010 by reaching 93 degrees. Olympia tied their previous record of 95 on Sunday, originally set in 1953. McChord Field in Tacoma soared to 96, Everett hit 89 and Port Angeles reached 90 degrees. Even Stampede Pass in the Central Cascades near 4,000 feet hit 86 degrees for a record high. Coastal communities were in the 80s.

More on the region’s hot weather: Dangerous heat has arrived in Washington; highs in the 90s

Driving this first heat wave of the year is the combination of strong high pressure aloft and low-level air flow moving from inland toward the outer coastline. These conditions also have generated lower humidities, amplifying wildfire behavior concerns if any fires were to start, particularly in the Cascades. Some Western Washington counties have initiated outdoor burn bans. Check with local fire districts to learn if an outdoor burn ban is in place in your area.

Monday and Tuesday look to be the warmest days this week, likely falling just shy of daily records. Highs will again climb into the 90s in many Western Washington interior locations. Heading down Interstate-5 (I-5) Highway toward Portland, some spots could crack the 100-degree mark. In the Cascades, freezing levels will exceed 15,000 feet, above the height of Mt. Rainier.

Summer heat wave extending into the night

From a health perspective, it is not just the heat of the day that is concerning, but the heat sticking around through the night. With such short nights this time of year, temperatures have limited time to cool down. Lows have only dropped into the upper 50s to mid-60s. It is important that everyone find a means to cool off for at least a few hours each day in an air-conditioned environment and stay hydrated by drinking plenty of water.

More from Ted Buehner: When will 2021’s ‘Heat Dome’ return to summer in Seattle?

Some cooler conditions can be found near the beaches in the North Sound, such as the San Juan Islands, Whidbey Island and Port Townsend, all with highs ranging from the mid-70s to mid-80s.

Relief from the heat though is in sight. The strong high pressure aloft is forecast to ease inland starting Wednesday and that subtle change will permit cooler onshore breezes to begin moving ashore. The outer coast and areas along the Strait of Juan de Fuca into the North Sound should feel some cooling on Wednesday through the end of the week. However, any cooling for central Puget Sound south to Portland will struggle to feel much cooling with highs remaining in the mid-80s to lower 90s.

By Thursday and Friday, sunshine will continue but high temperatures across the region will likely be around 10 degrees or so cooler than early this week. Readings should drop down to around 80 degrees in the interior – still above average – while the outer coast cools to 65-75 degrees with some marine clouds making an appearance.

The rise in onshore airflow later this week is expected to create windier conditions along the east slopes of the Cascades that could fan the ongoing wildfires in those areas. Blustery conditions are also possible through the Strait and nearby locations.

Looking ahead into much of the rest of this month, it appears there is no rain in sight with temperatures remaining warmer than average. July is the warmest month of the year and this month is following that trend.

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Ted Buehner is the KIRO Newsradio meteorologist. You can read more of Ted’s stories here and follow him on X.