Dense Fog Advisory for North Oregon Coast Range Lowlands, Central Oregon Coast Range Lowlands, Lower Columbia River and Tualatin Valley, Oregon, and 11 more areas

Ended at 3:22 AM PST, Monday, November 2, 2026.

Issued by the National Weather Service in Portland at 8:44 PM PST, Sunday, November 1, 2026.

Areas: North Oregon Coast Range Lowlands; Central Oregon Coast Range Lowlands; Lower Columbia River; Tualatin Valley; Inner Portland Metro; East Portland Metro; West Central Willamette Valley; East Central Willamette Valley; Benton County Lowlands; Linn County Lowlands; Lane County Lowlands; Cowlitz County Lowlands; North Clark County Lowlands; Inner Vancouver Metro; East Clark County Lowlands.

The Weather Service's text

WHAT...Visibility one quarter mile or less in dense fog.

WHERE...Portions of northwest and west central Oregon and southwest Washington.

WHEN...From 1 AM to 10 AM PST Monday.

IMPACTS...Low visibility could make driving conditions hazardous.

What to do

If driving, slow down and leave plenty of distance ahead of you. Pedestrians and cyclists should wear bright or reflective clothing to increase the chances of being seen by others in poor visibility conditions.