It's been a relatively mild and calm winter in Toronto and the GTA, but the story has changed this weekend.
A special weather statement has been issued for much of the Golden Horseshoe as snow moves through the region Saturday afternoon and evening into Sunday morning.
Environment Canada's Peter Kimbell - who is a warning preparedness meteorologist - says for Toronto, the driving will "be getting progressively nastier as the evening wears on."
Toronto is expected to top out at 8 to 10 centimetres total when the snow and blowing snow stop Sunday morning.
However, "the worst is for sure in the Niagara [region] and Hamilton - probably between Grimsby and Stoney Creek. That area is where they're probably getting a lot of the winds off the lake," Kimbell said.
Anywhere from 15 to 25 centimetres total is expected from Burlington down through Niagara.
Frigid temperatures
The bigger threat, though, is the frigid cold temperatures, and while Saturday afternoon sat at about -14 C, the worst was yet to come.
"That's actually positively balmy compared to what it's going to be Sunday night," Kimbell told NEWSTALK1010's Ted Woloshyn Saturday afternoon. "The windchills are going to increase as time wears on."
Windchills will bottom out at -31 C Saturday evening and -38 C Sunday evening, after a daytime high of just -16 C.
The weather agency's Steven Flisfeder confirms there is a risk of frostbite and anyone who needs to be outside dress accordingly.
"We start to introduce risks of frostbite around windchills of -20," he said. "As we get towards -30 windchills, it's more of an imminent threat within 30 minutes, and as it gets colder than that, it's even worse."
Flisfeder says any time outside over the next 36 to 48 hours should be limited to none, if possible.
Slick, slippery roads
By 2 p.m. Saturday, Toronto Transportation confirmed 200 salting trucks were out on the city's roads, with plows hitting the highways later in the afternoon and the main roads later in the evening.
But Mark Mills, superintendent of road operations, told NEWSTALK1010 that anyone heading out needs to be prepared for slick road conditions.
"We ask [motorists] to please slow down, adjust your speed, give yourself some extra time, be mindful for our pedestrians and cyclists who are out there."
The OPP had recorded at least 150 collisions across the GTA by 5:30 p.m. Saturday.
Mills confirmed that despite the cold, there are ways to keep the salt working including using a byproduct of beet - basically, beet juice.
Delays and cancellations
There are dozens of delays and cancellations at Pearson Airport due to storm conditions throughout the eastern seaboard and parts of the midwest.
If you're flying out to Ottawa, Montreal, Halifax, Boston, Cleveland or Chicago, be prepared for interruptions. You can check the status of your flight here.
Billy Bishop Airport is also reporting some delays and cancellations, which you can check here.
Conditions are expected to improve by Monday, a daytime high of -9 C is forecast for Toronto.
- with files from Claude Feig