Environment Canada is warning of near-zero visibility in Metro Vancouver and the Fraser Valley areas of British Columbia as a high-pressure system brings dense fog.
The weather agency says the ridge of high pressure over southern parts of the province has created favourable conditions for low clouds and fog.
It is warning that travel may be hazardous as visibility can suddenly be reduced to zero for drivers commuting to work.
The forecast says the fog is expected to lift slowly later today but may form again in the evening.
Arrivals and departures at Vancouver International Airport have been minimally affected, with some delayed flights but no cancellations as of this morning.
Environment Canada says the onset of winter weather continues for other parts of B.C., with the southern Peace region including Fort St. John facing a flash freeze where temperatures are forecast to drop rapidly and create icy conditions.
