Portland, Oregon – A weather pattern split could deliver either summer’s hottest stretch or an unseasonably cool, stormy turn across western Oregon by Tuesday. Highs could top 99°F under hazy skies—or struggle to reach the 80s with clouds and thunderstorms.
According to the National Weather Service in Portland, forecasters are monitoring a compact area of low pressure forming over northern California. Its path remains uncertain, but a northern track would pull moisture into Oregon starting late Tuesday, triggering cooler temps and a higher risk for rain and lightning through Thursday. If it stays south, heat and haze will dominate, with highs climbing into the upper 90s.
Forecast models are trending toward the cooler, wetter solution, which would bring increased cloud cover and scattered thunderstorms to the Willamette Valley, including Eugene, Salem, and Portland. The hotter outcome—featuring dry conditions and smoky skies—is becoming less likely but not off the table yet…