Motorists are advised to be extra cautious on Tuesday evening as Environment Canada warns of widespread fog in Toronto and the GTA.

Many portions of southern Ontario are expected to be enveloped in fog late Tuesday until Wednesday morning, the forecaster said in a special weather statement.

Visibility could be reduced to 200 metres or less.

Dense fog was also an issue in the morning, prompting Porter Airlines to issue a special weather advisory for Toronto, Sudbury and Windsor airports and warning travellers to check their flight status.

Click here for the full weather forecast.

The special weather statement is in effect for:

  • City of Toronto
  • Windsor-Essex-Chatham-Kent
  • Sarnia-Lambton
  • Elgin
  • London-Middlesex
  • Simcoe-Delhi-Norfolk
  • Dunnville-Caledonia-Haldimand
  • Oxford-Brant
  • Niagara
  • City of Hamilton
  • Halton-Peel
  • York-Durham
  • Huron-Perth
  • Waterloo-Wellington
  • Dufferin-Innisfil
  • Grey-Bruce
  • Barrie-Orillia-Midland
  • Cobourg-Colborne-Western Northumberland County
  • Peterborough-Kawartha Lakes
  • Bancroft-Bon Echo Park
  • Parry Sound-Muskoka
  • Haliburton
  • Renfrew-Pembroke-Barry’s Bay
  • Algonquin
  • Burk’s Falls-Bayfield Inlet