Hot weather continues in western WA, but why is this considered ‘extreme heat?’

The “extreme heat advisory” for the greater Seattle-Tacoma area has been extended until 5 a.m. Wednesday.

“We’ll see temperatures still getting up into the low 90s for a lot of areas,” National Weather Service meteorologist Kirby Cook said. “If you’re in some of the Cascade valleys and foothills, we may see some mid-90s tomorrow.”

Some are raising eyebrows that the western Washington weather merits an extreme heat advisory, pointing out that temperatures in Phoenix are expected to hit 100 degrees twice during the same time period, though Phoenix is under a lower “excessive heat” advisory.

‘Extreme heat advisory’ based on typical conditions

Cook said the National Weather Service bases its advisories on what is more typical for any given location.

“The impacts associated with heat in various parts of the country are going to be different based on the climatology there, as well as the ability for the community to manage those kinds of weather conditions,” he explained.

On average, daily high temperatures in the greater Seattle area in July and August stay below 80 degrees.

Fewer homes in King, Pierce, and Snohomish Counties are equipped with air conditioning than those in other parts of the country, although census data show the percentage jumped from just 44% in 2019 to 64% in 2023.

Slightly cooler temperatures ahead

For those of us Pacific Northwesterners who pull down the blinds and position ourselves in front of the oscillating fan when the mercury rises, Cook said there is a little relief ahead.

“We will start to see a little more cool-down going into Wednesday,” Cook shared.

However, he cautioned, “I kind of want to throw some air quotes around that cool-down. We’re talking about temperatures in the interior and the metro area in the mid to upper 80s on Wednesday, so it’s still going to be above normal, but we’ll be cooler than today [Monday] and tomorrow.”

Those further east should be aware of storms.

“It does look like we will have the potential for some thunderstorms in the afternoon and evening, starting tomorrow, mainly over the Cascade Mountains. So if you’re up in the mountains tomorrow afternoon and evening, you might hear some thunder,” Cook shared.

He said the risk of a storm in the lowlands is slight, although it will likely feel “muggy” in the Seattle metro area, so you can contemplate having a bad hair day as you sit in front of your fan.

Read more of Heather Bosch’s stories here.

Follow @http://www.twitter.com/heatherbosch