Advisory in effect as thick fog blankets most of southern Ontario

A school bus is seen driving in the fog north of London, Ont. on Friday, Sep. 17, 2021. (Sean Irvine / CTV London)

London and most of southern Ontario is under a thick blanket of fog Wednesday morning.

Environment Canada has issued a fog advisory, warning that dense fog has developed with near zero visibility in some areas.

Visibility is expected to improve near midday as the fog clears, but in the meantime, travel could be hazardous.

Several bus routes have been cancelled in the London region, as well as in Huron-Perth.

Here's a look at the rest of the forecast

Wednesday: Cloudy. Periods of rain beginning this afternoon. Fog patches dissipating near noon. Wind becoming west 30 km/h gusting to 50 late this afternoon. High 12.

Wednesday Night: Periods of rain ending near midnight then cloudy. Wind west 30 km/h gusting to 50 becoming light after midnight. Low plus 1.

Thursday: Cloudy. High plus 4.

Friday: Cloudy with 60 per cent chance of rain. High 7.

Saturday: Cloudy with 60 per cent chance of showers. Windy. High 7.

Sunday: Cloudy. High plus 5.

Monday: Cloudy with 30 per cent chance of showers. High 7.