TORONTO - A steep drop in temperatures over a short period of time created icy, treacherous driving conditions across much of Ontario today.

Environment Canada issued a special weather statement for many areas in southern and eastern Ontario, warning of the icy weather.

Communities in central Ontario including Owen Sound and Barrie were warned to expect flurries and blowing snow.

In southern Ontario, including the Toronto area, many roads were slippery and slow although traffic was lighter than usual due to people taking the week off work.

The blast of winter began with wet snow and rain Tuesday afternoon, followed by plummeting temperatures overnight which created slippery roads and sidewalks.

Provincial police in Peterborough say they responded to 41 minor collisions since Tuesday, with four of them involving injuries.

However, police at Toronto's two collision reporting centres said they had no weather-related incidents as of late this morning.

The mixture of rain and wet snow also caused flight delays and cancellations at airports in Toronto, Ottawa and Montreal on Tuesday night.

Airlines are encouraging anyone with a flight today to check online for possible delays.

Provincial police in Sudbury are reporting a spate of single-vehicle collisions in the area. They are warning drivers to avoid travelling on Highways 69 and 17 due to black ice and slippery conditions.

Meanwhile, a stretch of Highway 11 between North Bay and Cobalt was reopened after being closed overnight due to dangerous driving conditions.