Oregon – A dull gray haze sits low across eastern Oregon this morning, muting hillsides and blurring headlights as winter settles into the valleys. Cold air is locked in place, and the stillness carries consequences for both drivers and breathing conditions on MLK Day.
According to the National Weather Service in Pendleton, an Air Stagnation Advisory remains in effect until 4 p.m. Tuesday. A persistent temperature inversion and light winds are trapping pollutants near the surface across central, north-central, and northeast Oregon, along with parts of southeast Washington.
In Pendleton, Hermiston, La Grande, and the Columbia Basin, patchy freezing fog is adding another layer of concern. Visibility may drop quickly before midmorning, especially near rivers and low-lying roads. With temperatures in the upper 20s to near 30, fog can freeze on contact, creating slick stretches on I-84, Highway 11, and rural connectors.
Air quality may deteriorate through the day. People with asthma, heart disease, or other respiratory conditions are urged to limit outdoor activity. Wood burning should be reduced where possible. To be fair, the air may look calm, but stagnant conditions allow pollution to build quietly.
By Wednesday, areas of freezing fog persist early, followed by partial sunshine and highs in the upper 30s. The pattern remains slow to change, with cold nights and repeated fog cycles continuing into late week.
Drivers should slow down in fog, use low-beam headlights, and leave extra space. Residents should plan for cold mornings and limited air mixing until midweek improvements arrive.
How thick is the fog where you are this morning? Share what conditions look like on your drive.
Five-Day Weather Outlook for Pendleton, OR
MLK Day: Patchy freezing fog early, partly sunny, high near 40
Tuesday: Freezing fog early, partly sunny, high near 37
Wednesday: Areas of freezing fog, then mostly sunny, high near 37
Thursday: Patchy fog early, partly sunny, high near 38
Friday: Morning fog possible, partly sunny, high near 38
