Thick fog prompted the cancellation of school buses across much of Lambton-Kent Tuesday morning with students set to return to class following the long Family Day weekend.
Buses in Zones 1 to 6 did not make the morning run but are to be back out on the roads in the afternoon.
Hull Bus Lines operating for Aamjiwnaang First Nation and Sarnia Community Living Wawanosh Day Program were also cancelled for the morning as were buses from Kettle Point to high schools in Forest and Sarnia.
Environment Canada issued a fog advisory for Sarnia-Lambton with thick fog reducing visibility to nil at times.