Oregon Heat Wave Could Push Columbia Basin to 105 Degrees as Fire Weather Warnings Expand

With temperatures potentially reaching 105 degrees in the Columbia Basin, several heat and other weather advisories have been issued for northwest Oregon and southwest Washington.

Meteorologists Warn of Extreme Heat Across Oregon This Week

The first heat advisory came into effect for the Portland metro area and mid-Willamette Valley this morning.

At the same time, an extreme heat watch comes into effect for the eastern Columbia River Gorge and Columbia Basin. Light smoke high up in the atmosphere is also expected, so moderate to poor air quality issues are expected in central and eastern Oregon, but this is unlikely to extend to the west side of the state.

Driven by incoming monsoonal moisture, high heat, and active regional wildfires, the National Weather Service issued multiple weather hazards across Oregon and the Pacific Northwest:

• Red Flag Warnings (Central & Southern Oregon): A Red Flag Warning is in effect from 11 AM to 11 PM Wednesday for portions of central and southern Oregon (including the Southern Blue Mountains, Central Mountains, and Southern Deschutes National Forest). Expect isolated to scattered dry thunderstorms, wind gusts up to 35 mph, and lightning on dry fuels, creating a high risk for rapid wildfire spread.

A separate Fire Weather Watch covers the Cascades and Siskiyous for Wednesday due to similar lightning and gusty outflow threats.

• Heat Advisories (Western, Central & Eastern Oregon): A Heat Advisory runs from Tuesday morning through Wednesday night for the Portland Metro area, Western/Central Columbia River Gorge, and the Willamette Valley, where temperatures will climb to 95-100 degrees. Further east, an advisory extends through Thursday night, with afternoon highs reaching 101-105 degrees in the Columbia Basin, posing major heat-related illness risks.

• Air Quality & Smoke Advisories: The Oregon Department of Environmental Quality has active smoke and air quality advisories across multiple counties (including Baker, Harney, Malheur, and Jackson counties). Heavy particulate matter from regional wildfires is causing fluctuating, unhealthy air quality levels, prompting warnings for vulnerable populations to stay indoors.