Santa Claus may need some extra help from Rudolph Sunday while flying over southwestern Ontario.
A fog advisory has been issued for London, Middlesex, Sarnia-Lambton, Chatham-Kent, Windsor, Grey-Bruce and Huron-Perth counties.
Near zero visibility is expected in some areas.
Environment Canada is recommending if driving and if visibility is reduced to turn your lights on and maintain a safe following distance.
Visibility is anticipated to improve Christmas morning.
If needed, Environment Canada said the advisory may expand.
