Fog, including freezing fog in some areas, played havoc with traffic Monday morning.
Several accidents were reported, centering on the Hockinson and Brush Prairie areas.
Meanwhile, the morning commute was very slow on the freeways. Between 8:30 and 9 a.m., for example, Interstate 5 was backed up to the Main Street exit in Clark County, forcing heavy traffic onto side streets.
The National Weather Service warned that drivers should be prepared for slick roads and the possibility of low visibility areas until the fog lifts.
Most flights at Portland International Airport were on time, according to the airport’s website.
The Southwest Clean Air Agency’s monitors show air quality has nudged into the “unhealthy” zone in Vancouver and was nearly as bad in Yacolt, where it was considered unhealthy for sensitive groups.