PORTLAND, Ore. — A four-day heat wave is bringing record-breaking temperatures to Portland through Friday, when highs are expected to reach near 100 degrees.
The National Weather Service has issued an Excessive Heat Warning for the Interstate 5 corridor, including Eugene, Oregon and Longview in southwest Washington, through Friday evening.
"The weather service uses the verbiage ‘Excessive Heat Warning’ when they believe we’re going to hit 100 degrees or better," KGW meteorologist Rod Hill said.
Wednesday marked the start of the heat wave. Highs in Portland climbed to 102 degrees on Thursday, which set a new record for the latest in the year the city has hit the 100-degree mark. Friday could hit near 100 degrees. Portland has never reached as hot as 100 degrees on that date, Sept. 6, according to Hill.
"If we hit 100 degrees, it would be the latest in the season we’ve ever done so. We’ve never hit 100 degrees past tomorrow’s date," Hill said Wednesday morning.
Saturday will be the last day of the heat wave, with highs reaching into the low 90s. Temperatures will start to cool off slightly on Sunday, but it will still be mostly sunny and highs will be in the mid-80s. There's a shower chance on Tuesday and Wednesday of next week, Hill said.
In addition to possible record-breaking temperatures, PDX is inching closer to surpassing the record for the number of 90-degree and above days in a year. The all-time record is 31 days, set in 2018, according to Hill.
"This Saturday, if the forecast holds true, will become the 28th 90 plus-degree day of the year," Hill said.
Air Quality Advisory
An Air Quality Advisory is also in effect through Friday for much of inland Oregon, including Portland and Salem, and southwest Washington.
"High levels of ozone in the lower atmosphere is a concern as temperatures rise to near 100 degrees and wildfire smoke increases as east winds migrate smoke over the Cascades and into the Willamette Valley," Hill said.
As of early Thursday morning, air quality numbers in Portland were moderate.