Medford, Oregon – Drivers across parts of northern California and southern Oregon could encounter hazardous travel conditions overnight into Tuesday morning as dense freezing fog settles into valleys on both sides of the border, sharply reducing visibility and creating slick roads.
According to the National Weather Service in Medford, a Freezing Fog Advisory is in effect from early Tuesday morning through late morning for the Scott Valley in Western Siskiyou County, California, including Greenview, Etna, Fort Jones, and Callahan. Visibility could drop to one-quarter mile or less, with a thin glaze of ice possible on untreated roads and bridges.
The freezing fog threat extends into southern Oregon, where the Illinois, Applegate, and Rogue valleys are also under an advisory through Tuesday morning. Communities including Medford, Ashland, Grants Pass, Jacksonville, Cave Junction, and Rogue River may see rapidly changing visibility during the morning commute as fog thickens in low-lying areas.
At the same time, an Air Stagnation Advisory remains in effect across valleys in Jackson and Josephine counties through early Friday. A strong area of high pressure is trapping pollutants near the surface, leading to poor air quality that could affect people with respiratory conditions. Outdoor burning restrictions are likely to remain in place as ventilation stays poor.
The combination of freezing fog and stagnant air increases the risk for slick roads, especially during the early morning hours when temperatures remain below freezing. Even after fog begins to lift later in the morning, shaded areas may stay icy longer.
Drivers are urged to slow down, use headlights, and leave extra following distance. Residents with breathing issues should limit outdoor activity and follow medical guidance during periods of reduced air quality.
Freezing fog is expected to dissipate by late morning Tuesday, but stagnant conditions may persist through the week. Additional advisories could be issued if fog redevelops or air quality worsens.
