70-degree days, 7 p.m. sunsets ending this week with fall arriving
Sep 23, 2024, 6:29 AM | Updated: 2:52 pm
(Getty Images)
The fall equinox was early on Sunday morning. Welcome to the first full week of fall.
This week’s weather will involve a mix of late summer and early fall weather. Clouds blanketing Western Washington Monday morning are expected to give way to afternoon sunshine as higher pressure aloft builds over the region. High temperatures from the Puget Sound area south toward Portland are expected to rise above 70 degrees – close to this week’s average highs, while the north interior and the coastal regions will warm into the mid-60s, again near the average highs.
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Tuesday is anticipated to be the warmest day of the week with western interior temperatures warming into the 70s under plenty of sunshine. Tuesday will also have the final 7 p.m. sunset of the year.
Then here comes wetter fall weather. A pair of Pacific frontal systems are forecasted to move onshore impacting the rest of the work week. The first system is expected to spread light rain across the region Wednesday, and the second stronger system will arrive Thursday with more rain.
Temperatures will be much cooler the rest of the work week with highs reaching only into the 60s. By Friday, lingering showers are expected to taper off. Reflecting a taste of fall, snow levels in the Cascades are anticipated to drop near 6,000 feet Friday, giving higher elevations a fresh dose of snow.
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Looking ahead to the final weekend of September, higher pressure aloft is anticipated to build over the Pacific Northwest revealing more sunshine and temperatures warming well into the 60s. The Seattle Mariners return home for their final three-game series of the season against the Oakland A’s with the stadium roof quite likely open. The Sounders and Reign also play during the weekend next door at Lumen Field with dry conditions.
If longer range guidance holds true, the dry weather should hold into the first half of next week before wetter fall weather returns later in the week. Overall, autumn has arrived and so has the mix of early fall-like weather.
Ted Buehner is the KIRO Newsradio meteorologist. You can read more of Ted’s stories here and follow him on X.