Toronto is being warned to expect "severely cold" wind chills into Sunday night, prompting an Environment Canada meteorologist to urge residents to stay inside if possible.

An extreme cold warning for the city remains in place, a day after a winter storm brought at least nine centimetres of snow to Toronto, leaving roads slippery and hard to navigate.

In its warning, Environment Canada says temperatures will dip to –24 C on Sunday night. Wind chill values will make it feel like between – 35 and – 40.

"It's going to be quite frigid," Steve Flisfeder, meteorologist for Environment Canada, told CBC Toronto on Sunday.

"Tonight is definitely going to be the worst that we've seen."

Flisfeder said frostbite can develop in minutes under the expected conditions.

'Bundle up, wear layers'

"Limit your time outside. But if you do have to go out for any reason, bundle up, wear layers, wear hats, scarves, mitts. Frosbite is definitely a potential risk for any exposed skin."

Pet owners are also urged to limit the amount of time that pets spend outside in the cold. The rule of thumb is, if it is too cold for you, it is too cold for your pets.

A bitterly cold arctic airmass that has nearly all of Ontario in its icy grip, from north to south, has brought the chilly temperatures and it is expected to stick around for the rest of the weekend, Flisfeder said.

Flisfeder said the air mass means the high temperature is expected to be –12 C on Monday and the low temperature is expected to be –20 C or colder on Monday night into Tuesday.

The forecast calls for wind chill values on Monday of – 38 in the morning and – 22 in the afternoon.

A Portuguese Water Dog surveys the snow in Toronto after a winter storm brought about nine centimetres to the city on Saturday. (Alan Habbick/CBC)

Street nurse and homeless activist Cathy Crowe says the extreme cold is a source of worry for her because the system is so full there are no places for people to go.

"A lot of people of course are worried about freezing deaths, about hypothermia, about frostbite, potential injuries from the cold, but also what's happening inside places is people are really, really sick and that the shelters are full," Crowe told CBC Toronto.

"We reached a peak this week of 1,050 people that couldn't get into real shelters and they're staying in places like this dome behind me, church basements, drop-in floors, sleeping in chairs and places like the building at the CNE. Those are not real shelters and they're super crowded and they're super unhealthy."

Street nurse and homeless activist Cathy Crowe says a lot of people are worried about freezing deaths, hypothermia, frostbite, and potential injuries from the cold. (CBC)

Shelter system under significant pressure

Todd Orvitz, director of strategic and policy solutions at the City of Toronto, said the shelter system is under a significant amount of pressure.

But he said over the last couple of days, they have not had to turn anybody away.

"When we do have an extreme cold weather alert as we do right now, we are able to activate some additional spaces that we have so that we can ensure that everyone that wants to come inside can," Todd told CBC Toronto.

"We also increase the number of street outreach teams we have available, so folks who are going out there and checking in on people who are sleeping outside to offer them an opportunity both to come inside and just check up on them and make sure they're doing okay."

5 to 10 cm of snow fell in Toronto

The edge of a major storm south of the Great Lakes that is still in the U.S. brought the snow to Toronto and other areas in Ontario on Saturday.

About nine centimetres of snow was recorded at the weather station at Toronto Pearson International Airport, but the federal weather agency saw a range of five to 10 centimetres in the Greater Toronto Area.

This Bernese Mountain Dog is "loving the snow piling up in Upper Stoney Creek," wrote one Twitter user on Saturday. The community is part of Hamilton. (@guitrmn/Twitter)

Drivers sliding into ditches, trees, other vehicles

Toronto police said about 100 crashes were reported from 1 p.m. on Saturday to 7 a.m. on Sunday, with drivers sliding into ditches, clumps of trees, and other vehicles.

No serious injuries were reported, according to Const. Allyson Douglas-Cook, spokesperson for the Toronto Police Service.

"We're stressing the importance of people being aware of their surroundings when driving," she said on Sunday. "Slow down, give yourself from space."

In Hamilton and surrounding areas, anywhere from five centimetres to 45 centimetres of snow fell on Saturday, with Hamilton Airport officially recording 15 centimetres of snow.

Relief from extreme cold coming Tuesday

Environment Canada, however, says there is relief from the extreme cold in sight.

On Tuesday, a milder airmass is forecast to arrive in Toronto, bringing a high temperature of –5 C, with wind chills around –10 to –15.

A robin tries to keep warm in some bushes in downtown Toronto as the city continues under an extreme cold warning. (Muriel Draaisma/CBC)

City crews plowing roads

Meanwhile, the city says it is continuing to plow main and local roads and clear sidewalks after Saturday's snowfall.

Local road plowing commenced overnight and will continue until approximately 8pm this evening. Cleanup operations on local roads will resume on Monday. —@TO_WinterOps

Pearson is reporting some cancellations due to the extreme cold. Travellers are urged to check their flight status with airlines before leaving home.