A spokesman for the City of Montreal said it could take more than four days to remove the impressive amount of snow that has covered the municipality.
Environment Canada said a record-breaking 45 centimetres of snow has fallen at the Montreal-Trudeau airport, eclipsing previous local records held for the most snow fallen in the span of a day.
According to Jacques-Alain Lavallée, the city's spokesman, it usually takes the snow fleet four days to remove 20 centimetres of snow.
He said he does not think the snow-clearing time will be doubled.
City crews have been at work since 4:15 a.m., when the accumulation reached 2.5 centimetres.
More than 1,000 workers are on the streets of Montreal to help clear the winter mess.
The city said it urges people to respect parking signs for snow removal. Lavallée said the city has put in place 5,700 parking spots for people to move their cars off the streets. People can call 311 for more information.
Lavallée said snow-clearing operations will continue overnight and snow removal will begin at 7 a.m. Friday.
Montreal police were recommending that people stay home to make way for emergency vehicles.
Earlier today, police spokesman Danny Richer said several roads were being blocked on and off in downtown Montreal to allow snowblowers to go through and clear off the snow.
The city's police force has opened its command centre to coordinate with other emergency services.
Marie-Claude Desgagnés, a spokeswoman for the Montreal-Trudeau airport said a total of 225 of departing and incoming flights from the northeastern regions of the United States and Toronto were canceled as of 5 p.m.
Officials say strong winds in Montreal are the main cause for the cancellations.
On Montreal's public transit system, buses, metros and trains were still running, though slippery roads and poor conditions were causing delays.
Dozens of buses were stuck in the snow and others struggled to make it up slippery hills across the island.
Those most affected were bus lines that run on hills, including Mont-Royal and Parc Avenue.
The STM continues to urge commuters to take the metro rather than the buses until streets are cleared.
Laval's transit authority said some city bus services have been suspended due to the severe weather conditions.
A spokesperson for the service said transit on main routes is continuing and that all routes should be restored by rush hour.
Strong winds and heavy snow have knocked out power for about 2,600 customers in the Laurentians.
Hydro-Québec said the outages were triggered by power lines shorting out when they touched because of the wind.
The latest blast of winter weather comes only days after a storm knocked out power to more than 100,000 Hydro Quebec customers north and west of Montreal.
About 300 customers in the Laurentians and the Outaouais region have been without power since last Friday's storm.
The utility said it has 700 employees currently working to restore the outages.
François Giroux, a spokesman for Transport Québec, said many cars were immobilized on Highway 13 North between the exits for Highway 14 and 20.
At 8 p.m., Giroux said crews are trying to remove the cars stuck in snow in order to reopen the road to traffic.
Cars had been at a standstill for at least an hour.
Police were at the scene of a 15 vehicle pile-up about 50 kilometres west of Trois-Rivières earlier this afternoon.
The crash forced authorities to close down the westbound lanes on Highway 40 near exit 156.
Quebec provincial police said there were no injuries to report.
The early-morning winter wallop left roads snow-covered and highways treacherous in the Montreal area.