A storm that swept into southern Ontario earlier this week hit Toronto with its first heavy snowfall of the winter Saturday, slowing roads and highways to a crawl.

The storm brought cold temperatures and gave the Greater Toronto Area around 20 centimetres of snow.

Environment Canada had said the storm was "a heavy east to west band of snow off Lake Ontario extending into the Toronto area."

The forecast for Saturday evening and Sunday morning is calling for clear skies with a low of -11 C. There is a 30 per cent chance of flurries on Sunday in the Toronto region.

The snow began falling Friday night and kept provincial and municipal snowplows and salting trucks working overnight across the region.

Low visibility and slippery conditions caused several accidents, with cars spinning off the road.

The snow began hitting southern Ontario late Thursday, when a fast-moving storm out of Western Canada swept into the province and began moving westward.

The weather caused several accidents, including one that shut down part of Highway 400 after a tractor trailer fish-tailed and crashed.