Much of Southwestern Ontario was blanketed by fog Sunday.
Environment Canada issued a fog advisory for areas including Grey-Bruce, Huron-Perth, London-Middlesex, Elgin, Oxford, Sarnia-Lambton, and Chatham-Kent counties in the very early hours of the morning.
As of 5 a.m., the weather agency forecasted that the "locally dense fog will persist for a few more hours before dissipating."
By 8 a.m., the advisory had ended in Huron-Perth, London-Middlesex, Elgin, Oxford, and Sarnia-Lambton. Around 10:30 a.m., the advisory was lifted in Grey-Bruce and Chatham-Kent.
Drivers were warned that visibility could have been significantly and suddenly reduced in some spots, and to be cautious on the roads.