A fog advisory in Windsor-Essex and much of southern Ontario continues.
Environment Canada says areas of dense fog are expected to continue today.
Visibility may improve this afternoon and evening, but could deteriorate once again tonight as more fog is in the forecast.
Very poor visibility is being reported by Ontario Provincial Police on Highway 401.
School buses in Windsor-Essex were cancelled this morning but are running this afternoon.
Some flights at Windsor International Airport have been cancelled or delayed today and passengers are advised to check the status of their flight ahead of time.
Toronto Pearson International Airport says it has temporarily grounded some flights due to dense fog in the area causing low visibility for pilots.
On foggy days like today, air traffic controllers regularly assess visibility and adjust hourly arrival rates to maintain safe operations.