Oregon heat wave: When will Willamette Valley see cooldown?

The Willamette Valley is on the verge of a historic stretch of heat, but a slight cooldown is just around the corner.

Both Salem and Eugene have posted record-breaking, triple-digit heat the past three days and were forecast to crack the 100s Monday and Tuesday as well. Five straight days over 100 would tie a record for consecutive days above 100 first set in July 1941 in Portland.

“It does look like we’re on track to set that record,” National Weather Service meteorologist Hannah Chandler-Cooley said.

Salem’s high temperatures over the past three days were 103 Friday, 103 Saturday and 103 Sunday. All were records.

Eugene’s high temperatures have been 101 Friday, 104 Saturday and 103 Sunday. All three were also records.

Cooler Willamette Valley temperatures on the way amid Oregon heat wave

Cooler temperatures, or at least less-extreme heat, is on the way. High temperatures are forecast to drop into the low 90s and even upper 80s in the later half of the week.

“We’re getting an upper level of low pressure swinging into British Columbia that has a cool front and should bring us a small influx of cooler air,” NWS meteorologist David Bishop said. “We should also get a little more onshore flow from the Pacific.”

Basically, the ridges of high pressure — or heat dome — is forecast to be pushed eastward. That will keep temperatures roasting hot in Eastern Oregon and the Intermountain West, but it should bring a break for western Oregon.

Long-range, temperatures are expected to stay in the 80s to 90s range across the coming eight to 16 days, without any extreme heat forecast currently.

“I think the biggest thing people will notice is that yes, we’re not in the 100s, but it’s almost more important that our low temperatures will drop back into the 50s,” Chandler-Cooley said. “In this heat wave, nighttime temperatures being in the 60s and even upper 60s makes it really hard to cool buildings down at night, especially in places that don’t have adequate cooling systems.”

Zach Urness has been an outdoors reporter in Oregon for 16 years and is host of the Explore Oregon Podcast. Urness is the author of “Best Hikes with Kids: Oregon” and “Hiking Southern Oregon.” He can be reached at zurness@StatesmanJournal.com or (503) 399-6801. Find him on X at @ZachsORoutdoors.