The temperature is set to rise over the next two days in Toronto, following a day in which commuters drove to work through snow and freezing rain and headed home on slushy roads and under fog.

In the very early hours of Monday morning, Toronto and much of southern Ontario was hit with overnight snow and then freezing rain, which made the drive to work a mess in many places.

The problematic weather resulted in the delays or cancellation of scores of flights at Pearson International Airport and made a slippery mess of Toronto-area roads. There were multiple collisions on the highways around the city, with traffic slowing to a crawl on many major routes. The OPP reported almost 500 collisions on Ontario roads, and multiple incidents of vehicles sliding into ditches and guardrails.

On some routes, traffic slowed to a crawl as drivers dealt with low visibility, rain-splattered windshields and ice-encrusted roads.

The poor weather also led to school bus service being cancelled in school boards throughout the region.

By the late afternoon, much of the north end of the city was covered in slush.

David Phillips of Environment Canada said the sudden change was emblematic of the kind of weather we’ve been seeing this winter.

"It’s just this unprecedented, almost back and forth, yo-yo, pothole kind of weather," Phillips said. "It is really quite dramatic."

For example, he points out, the temperature at Pearson International Airport hit a balmy 15 C on Jan. 13, but fell all the way to -12 C just nine days later.

The weather will be very different by Tuesday, with Toronto to hit highs of 8 C with the possibility of thunderstorms.

It is expected to be even warmer on Wednesday, with the mercury going as high as 11 C.

The unseasonably high temperatures could well break decades-old daily temperature records, CBC meteorologist Claire Martin reported.

Temperatures are then expected to fall below freezing in the latter half of the week.

With a report from the CBC's Jeff Semple and files from The Canadian Press