UPDATE: Fog advisory ended for areas of southern Ontario

The fog advisory has ended for the city of Toronto, but does remain in effect for much of the GTA.

Niagara, Hamilton, Halton region, Dufferin and York-Durham region are still under a fog advisory.

Police are advising motorists to use extra caution on the roads in those areas.

Persistent fog with visibility near zero is expected.

The reduced visibility could make for poor driving conditions throughout much of the province.

Drivers are being advised to turn on the full headlights on their cars.

Slow down & increase your following distance today. Use your low-beams NOT high-beams & fog lights if you have them.
Also #BePatient pic.twitter.com/36bJLAqKpU

— Peel Regional Police (@PeelPoliceMedia) January 22, 2017

The Greater Toronto Airports Authority said that the fog was not causing any flight delays Sunday morning.

With files from Corinne Van Dusen