Drivers in Ontario could experience “near-zero-visibility” for a third day as fog continues to blanket several parts of the province.

Environment Canada said that areas of dense fog will continue this morning, but that visibility should begin to improve during the middle of the morning for most areas.

The fog could persist into the afternoon, the national weather agency said.

“Visibility may be significantly and suddenly reduced to near zero,” it advised.

“Travel is expected to be hazardous due to reduced visibility in some locations. If visibility is reduced while driving, slow down, watch for tail lights ahead and be prepared to stop.”

Some of the regions under a fog advisory include, Toronto, Hamilton, Mississauga, Brampton, Newmarket, Pickering, Uxbridge, Oshawa, Vaughan, Richmond Hill, Markham, Burlington, Oakville, Caledon, Halton Hills, Milton, Niagara Falls, St. Catharines, Welland, Kitchener, Waterloo, Guelph, Cambridge, Brantford, Dunnville, Caledonia, Orangeville, Shelburne, Listowel, and Stratford.

Barrie, Orillia, Belleville, Cobourg, Brockville, Sudbury, Haliburton, Kingston, Napanee, Manitoulin Island, Peterborough, and Muskoka are also affected.