From around the region:
- GREATER TORONTO AREA: What you need to know about closures and cancellations as a major snowstorm slams the GTA.
- OTTAWA AREA: Travel excruciating due to record-breaking snowfall and wind gusts.
- HAMILTON AND NIAGARA AREA: Here's what's closed across Hamilton, Niagara and Halton as blizzard hits the region.
- KITCHENER-WATERLOO AREA: Schools closed, snow events declared in Waterloo region, Guelph and Wellington County. Get even more updates from the CBC Kitchener-Waterloo Storm Centre.
- LONDON AREA: London hit with about 20 cm of snow, causing citywide disruptions.
A winter storm of rare proportions blanketed much of southern Ontario with heavy snow Monday, causing widespread school closures and travel disruptions, leaving some stuck on a major highway for hours on end.
Environment Canada issued snowfall, winter storm or blizzard warnings for a stretch of the province spanning from the Cornwall area to the east, the Algonquin region to the west, and the Niagara and London regions to the south. By early evening ET, only a handful regions remained under alerts, mostly for snow squall warnings.
Toronto and Hamilton had been under a blizzard warning at one point early Monday, with between 40 and 60 centimetres of snowfall expected.
"It's probably true that this is a once-in-a-decade kind of event, especially the scale of it," said Steven Flisfeder, lead meteorologist with Environment Canada.
"Certainly, places along the Lake Huron shores and Georgian Bay shores have seen fairly significant lake-effect snow events that could give them similar snowfall totals, but for such a widespread area to receive such large amounts of snow is fairly rare."
It's also rare to see a blizzard warning issued for the Toronto region, he said.
Major roadways shut down
The snowfall forced the temporary shutdown of two of the city's major arteries, the Gardiner Expressway and the Don Valley Parkway. Police said the closures were to allow snowplows to clear the routes and help move any stuck vehicles. Those routes have since reopened.
While another major roadway, Highway 410, remained open, some drivers found themselves stuck for at least eight hours.
Those travelling by bus or train also faced hurdles, with the earlier highway shutdowns impacting the routes of some GO Transit buses serving the city's downtown Union Station terminal. Toronto's transit system was also affected as many buses and streetcars got stuck
"Customers will experience longer than normal wait and travel times," the Toronto Transit Commission said on its website.
Meanwhile on Queen West in Toronto just past Dufferin Street. <br><br>Four busses are stuck in the snow. <br><br>The drivers are standing outside of their busses directing traffic. Quite the scene here. <a href="https://t.co/XOnQhxlz3C">pic.twitter.com/XOnQhxlz3C</a>—@Devin_Heroux
Meanwhile, the wintry conditions led to the suspension of the UP Express train service that runs from Toronto's Pearson International Airport to the downtown core.
Late Monday evening, Metrolinx tweeted that service on the UP Express and GO Transit would be affected again on Tuesday.
To ensure we can provide safe & reliable transit for those who must travel we will temporarily reduce services for <a href="https://twitter.com/UPexpress?ref_src=twsrc%5Etfw">@UPexpress</a> <a href="https://twitter.com/GOtransit?ref_src=twsrc%5Etfw">@GOtransit</a> & <a href="https://twitter.com/GOtransitBus?ref_src=twsrc%5Etfw">@GOtransitBus</a> for Tues Jan 18. Schedule will be posted this evening. Thank you in advance for your understanding. 2/3—@MetrolinxSpox
At a late afternoon news conference, Toronto Mayor John Tory said the city will have to declare a special "snowstorm condition" to ensure its crews can remove snow on city streets left by the storm.
- What's happening in your area? See a map of Environment Canada's weather alerts for southern Ontario
- What's happening on the roads? See the latest from 511Ontario, which brings you updates from Ontario's Ministry of Transportation.
In the Ottawa-Gatineau region, Highway 7 was closed between Highway 417 and Kaladar because provincial police said plows couldn't keep it safe and multiple vehicles were blocking the road.
Police had warned of "zero visibility" on major highways in the region and advised people against taking them, saying they couldn't guarantee help right away if drivers run into trouble.
Ottawa was expected to see 30 to 50 centimetres of snowfall. City officials warned that it will take days to clean up, given the magnitude of the storm.
Up to 25cm and counting at the Ottawa Airport at 9 am. At 8 am there was 13cm. <a href="https://twitter.com/hashtag/ottnews?src=hash&ref_src=twsrc%5Etfw">#ottnews</a> <a href="https://twitter.com/hashtag/ottweather?src=hash&ref_src=twsrc%5Etfw">#ottweather</a> <a href="https://twitter.com/hashtag/ONStorm?src=hash&ref_src=twsrc%5Etfw">#ONStorm</a> <a href="https://t.co/ZRThCyo8t2">pic.twitter.com/ZRThCyo8t2</a>—@BlacksWeather
In the Kingston area, where total snowfall amounts of 25 to 40 centimetres were expected, Kingston Transit cancelled many routes on Monday.
In Hamilton, meanwhile, the public transport agency said late Monday afternoon it was experiencing "significant delays" on routes across the city, including some detours for a time.
Stay home if you can, officials say
Sgt. Kerry Schmidt of the Ontario Provincial Police (OPP) told CBC's Heather Hiscox on Monday morning that vehicles were spinning out and losing control on Highway 401 near Pearson International Airport, adding that plows were trying to keep up but hampered by snowfall and traffic volumes.
Meanwhile, Premier Doug Ford was on the streets of Toronto, where he told CBC News he was helping with shovelling and helping drivers who were stuck.
A number of communities also called off COVID-19 vaccination clinics for the day in light of the weather. Clinics were cancelled in Toronto, Niagara Falls, Stratford, Oshawa and across the Simcoe-Muskoka and Leeds, Grenville and Lanark health units.
Air travellers were also impacted by the snowy conditions. Dozens of flights to and from Toronto's Pearson airport were delayed or cancelled this morning, according to the airport's website.
Air Canada, meanwhile, posted an update saying flights through major airports in Ontario and Quebec "may be impacted by forecasted winter operational conditions."
Parts of Quebec expected up to 40 cm
Environment Canada also issued winter storm warnings for most parts of Quebec, with 25 centimetres of snow expected in the areas of Montreal and for the provincial capital, while the Gatineau region, close to Ottawa, could see up to 40 centimetres of snow before the end of the day.
Driving conditions deteriorated rapidly Monday afternoon across Quebec as multi-vehicle accidents triggered road closures.
The provincial police reported multi-car pileups, closing parts of three major highways around Montreal. Police said in a statement some people suffered injuries, but "none appear to be life-threatening at this time." Quebec Transport Minister François Bonnardel sent several tweets asking people to remain vigilant.
"Once again, I'm asking people to avoid travel," Bonnardel tweeted Monday.
The blast of winter weather sparked widespread school closures and cancellations across Ontario.
The Toronto, York, Halton, Hamilton-Wentworth and Ottawa-Carleton district school boards were among those that cancelled the planned return to in-school learning on Monday because heavy snow forced a halt to school bus services.
Closures weren't just hitting public schools in Toronto — some post-secondary schools cancelled in-person classes on Monday and library branches were also closed due to weather conditions.
"Our educators will do their best tomorrow," the Ottawa Catholic board said in a statement Sunday announcing the shift to remote education. "However, most had planned for a day of in-person learning, so a transition to a full synchronous learning day may need to be adapted."
Mail delivery was also put on hold in areas grappling with the storm. Canada Post said it was issuing a "red delivery service alert" for eastern and southern Ontario, meaning delivery would be suspended and agents wouldn't be sent out.
"Delivery will resume once conditions improve and it's safe to do so. The safety of our employees is our number one priority," it said in a statement.
With files from CBC News