At 1:05 a.m. on Tuesday, the National Weather Service released a dense fog advisory in effect until 9 a.m. for Lower Columbia River, Tualatin Valley, West Central Willamette Valley, East Central Willamette Valley, Benton County Lowlands, Linn County Lowlands and Lane County Lowlands.

“Visibility one quarter mile or less in dense fog,” can be anticipated according to the weather service. “Fog may not be uniformly dense across the region and drivers should expect rapid changes in visibility on roadways. Dense fog is most likely to occur in sheltered valleys and near waterways including lakes and rivers. Locales less sheltered from wind may instead see low overcast skies where only hilltops experience reduced visibility.”

News Source : https://www.oregonlive.com/weather-alerts/2026/02/dense-fog-advisory-affecting-oregon-until-tuesday-morning-limited-visibility.html