Tuesday morning's heavy fog has forced the cancellation of school buses in all zones in Sarnia-Lambton.
That includes service to Sarnia Christian School, Aamjiwnaang First Nation and Sarnia Community Living Day Programs.
School bus service to Walpole Island Elementary school is delayed by about two hours. All schools remain open for the day.
Service is expected to be normal in all zones during the afternoon as conditions improve.
Environment Canada posted a fog advisory on Wednesday night, noting poor visibility was expected. There was also the risk of freezing drizzle causing slippery conditions on area roadways.
Drivers are urged to slow down and take our time on the roads.