Environment Canada ended the fog warning for the city and surrounding areas shortly before noon Friday.  Prior to that, the advisory had been in effect since Wednesday.
The National Weather Service typically issues fog warnings when near-zero visibility is expected.  Large patches of fog could be seen in urban areas and southern Ontario during the second half of the week.
Toronto Pearson warned Friday morning that fog could affect its operations and encouraged travelers to check their flight status before arriving at the airport.

		Area weather may affect business this morning in Toronto Pearson.  Check your flight status with your airline before leaving for the airport.
	— Toronto Pearson (@TorontoPearson) November 4, 2022
Environment Canada expected the fog to clear late Friday morning to make way for a mix of sun and clouds.
It’s currently 14C in Toronto with a high of 18 expected later this afternoon.
The temperature will drop again to 14 degrees in the evening.