It will cost Montreal about $20 million to clean up about 20 centimetres of snow that fell on the city Tuesday and overnight, ending Wednesday morning.

City spokesman Darren Becker said the cleanup will take about a week.

"Yesterday, they were plowing all day, obviously a bit on reduced manpower because of the fact it was a statutory holiday, but nonetheless, crews were out," Becker said.

"As of [Wednesday] evening, the city is going to start its snow removal operation. There will be over 1,000 pieces of equipment and over 1,000 employees working basically around the clock," he said.

Becker reminded city residents to respect the no-parking signs. He said so far this winter, the city has had to tow an average of 3,500 cars during each snow-removal operation.

The weather is making travel tough for Quebecers, with slick and snow-covered roads in many regions after a storm blew through on its way to Atlantic Canada.

Dozens of cars ended up in the ditch overnight, but "there were no major accidents with injuries. We've been lucky," said Jean-Marc Rivest of the provincial Transportation Department.

Many flights were delayed or cancelled at Montreal's Pierre Elliott Trudeau International Airport, especially those heading to Atlantic Canada, which was hit even harder by the storm.

The snow started early Tuesday in southern Ontario and had moved east through Quebec and into Atlantic Canada by Wednesday morning. Environment Canada said the system would leave anywhere from 10 to 30 cm of snow across the region by Wednesday morning.