HeliJet and Harbour Air flights from Vancouver, Victoria and other locations on the South Coast were on hold early Wednesday morning until visibility improves.
At Vancouver International Airport some of the regional flights have also been cancelled again.
Craig Richmond, the CEO of the Vancouver Airport Authority, says YVR can handle the fog, but the smaller airports can't.
"Generally it's because they don't have the equipment in those smaller airports to get in in the worst kind of fog. It's just not worth the money," he said.
Richmond says fog can be really unpredictable, so it's hard for travellers to plan ahead, but he suggests people check with the airlines before heading out to the airport.