Thursday and Friday will be quite warm and likely the last warm weather period of the season. Highs in Western Washington will be above 25 degrees both days, including the Pacific Coast. Some locations in the Cascade foothills and from the South Sound south will likely break the 32-degree mark.
Some daily record temperatures could be broken, equaled or at least threatened later this week. At Seattle-Tacoma International Airport (SEA), Thursday’s record is 88 degrees – set in 1973 – and could fall from the latest forecast of 89 degrees. Friday’s record is 90 degrees, set in 2014. The weather forecast calls for highs of 87 degrees.
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In Olympia, Thursday’s record high is 91 degrees, set in 1973, and could be surpassed with a forecast high of 93 degrees. Friday’s record high of 89 degrees was set in 2014 and could be broken with a current forecast of 92 degrees. In Hoquiam, Thursday’s record high is 89 degrees, set in 1955, and the forecast is expected to eclipse that record.
This late summer warm weather period is caused by the build-up of a high pressure system over the Pacific Northwest combined with a low-level current drifting from the interior into the Pacific Ocean. This weather pattern often results in unseasonably warm temperatures. Average high temperatures in inland Western Washington range from 70 to 77 degrees Fahrenheit (21 to 25 degrees Celsius) in early September.
Despite the rainy second half of August, precipitation in much of Western Washington is well below the average for the year so far. Some places are up to 10 centimeters below average and large parts of the interior are considered unusually dry or affected by moderate drought, according to the latest drought monitor.
This late summer rise in temperatures above average will also increase the risk of wildfires. With the ongoing dry conditions, any fire has the potential to become very active and spread.
Help prevent local wildfires by not throwing burning materials from vehicles, tightening tow chains so they don’t drag on the pavement, and continuing to delay outdoor burning. Many counties have outdoor burning bans in place through the end of this month.
For anyone planning to attend the Seattle Seahawks’ season opening game on Sunday, it promises to be an ideal day for football, with plenty of sunshine and temperatures reaching 25 to 30 degrees in the afternoon.
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No significant rainfall is expected for the coming week and temperatures will be more summery and average, but long-range forecasts point to cooler and wetter conditions as the following weekend approaches.
So enjoy this warm, dry late summer weather. Autumn is just around the corner.
Ted Buehner is a meteorologist at KIRO Newsradio. Read more of Ted’s stories here Here and follow him on X, formerly known as Twitter.
