MEDFORD, Ore. – A cold, foggy start to the week is expected across southern Oregon, where a Dense Fog Advisory and Frost Advisory remain in effect through 9 a.m. PDT Monday. Patchy fog is reducing visibility to less than a quarter mile in parts of the Rogue, Applegate, and Illinois Valleys, while temperatures in rural spots are dipping near freezing.
According to the National Weather Service in Medford, temperatures between 32 and 35°F will allow frost to form in areas with clear skies—particularly near Ashland, Cave Junction, Shady Cove, and Jacksonville. However, thicker fog around Medford and Grants Pass may keep some surfaces just above freezing, limiting frost in those spots.
The Oregon Department of Transportation (ODOT) warns drivers along I-5, Highway 199, and Highway 62 to expect reduced visibility through midmorning. Motorists should slow down, use low-beam headlights, and maintain extra distance between vehicles.
Residents are advised to protect sensitive vegetation and outdoor plumbing from the cold. Frost can damage plants if left uncovered, and vehicles may need extra defrost time before travel. Conditions are expected to improve by late morning as fog lifts and sunshine returns.
High pressure will maintain cool, dry fall weather through midweek, with chilly mornings and mild afternoons continuing across southern Oregon.
