Toronto Hydro says thousands of its customers are without power as the city reels from an ice storm.

As of 10:44 p.m. Sunday, approximately 20,000 Toronto Hydro customers were affected by power outages.

Toronto Hydro said in a tweet they have received a number of reports about trees and wires down across the city because of the severe weather, leaving some customers in the dark Sunday evening.

"All available crews have been activated and will continue working overnight," the utility company said. "We know it's getting colder but can assure you that we have all hands on deck and are working as quickly & safely as possible."

Hydro One crews pack up after restoring power on a rural road near Lucan, Ont., on Sunday as tens of thousands were left without power in southern Ontario due to an ice storm. (Geoff Robins/Hydro One/Canadian Press) Earlier Sunday evening, Toronto Fire Service said on Twitter it was attending 24 downed wire calls and two transformer pole fires "likely due to freezing rain."

Outside of the city, Hydro One says more than 47,000 customers were without power as of about 11:40 p.m. Sunday night as freezing rain, high winds and ice pellets battered southern Ontario.

The utility company says that since the start of the storm it has restored power to more than 96,000 customers, but warns some in southwestern Ontario may be without power tonight.

Downed wires caused a number of power outages across southern Ontario on Sunday. (Geoff Robins/Hydro One/Canadian Press)

"We're definitely not out of the woods yet. It's tricky to tell what we will see overnight," Hydro One spokesperson Jay Armitage told CBC Toronto. "We've got 1,400 people who will head out as soon as dawn breaks to help get people back on as quickly and as safely as possible."

She added that the weather has made it difficult to get the necessary work done, but working during the night also poses its own difficulties.

"We do have crews overnight. We are going to be most effective once we see daylight once again."

Environment Canada warned earlier that an ice storm was "likely" on Sunday and outages were possible because trees and branches, laden with ice from the storm, could fall on power lines.

Hundreds of crashes on roads

Earlier on Sunday, Ontario Provincial Police said there had been nearly 1,200 automobile crashes in the Toronto area since the storm first hit on Saturday.

"This is significant and a lot for a weekend. The weather continues to blow the snow and ice," Sgt. Kerry Schmidt, spokesperson for the OPP's Highway Safety Division, told CBC Toronto.

​"It's going to be a tough evening. When this turns into rain, it's obviously going to get wet — a potential for flooding exists as well." Cars drive along Toronto's Lakeshore Drive as visibility diminishes through falling hail, snow, and rain. (Cole Burston/Canadian Press) "It's going to be a tough evening. When this turns into rain, it's obviously going to get wet — a potential for flooding exists as well."

Environment Canada issued freezing rain warnings across southern Ontario and parts of southern Quebec early Sunday because of a spring storm that could make driving a lot more difficult for the rest of the weekend.

The OPP has recommended that drivers cancel non-essential travel on the roads.

"It's not worth it," Schmidt said. "The conditions are going to deteriorate throughout the day."

Those taking the TTC may also face delays as the transit authority says service on Line 3 has been suspended because of ice on the rails. Shuttle buses are operating from Kennedy to McCowan stations.

<a href="https://twitter.com/hashtag/OPP?src=hash&ref_src=twsrc%5Etfw">#OPP</a> have been called to approximately 1200 collisions during the <a href="https://twitter.com/hashtag/OnStorm?src=hash&ref_src=twsrc%5Etfw">#OnStorm</a> <br>Roads are still wet and slushy<br>Avoid unnecessary travel <a href="https://twitter.com/hashtag/BeSafe?src=hash&ref_src=twsrc%5Etfw">#BeSafe</a> <a href="https://twitter.com/hashtag/OPPTips?src=hash&ref_src=twsrc%5Etfw">#OPPTips</a> <a href="https://t.co/Z0eTKunoBt">pic.twitter.com/Z0eTKunoBt</a> —@OPP_HSD

3 warnings in effect for Toronto

Toronto remains under both freezing rain and rainfall warnings. The city endured freezing rain and ice pellets late Saturday and into Sunday morning, with snow falling in some areas.

Environment Canada issued the rainfall warning for the city and surrounding area, saying rainfall amounts could be between 25 and 35 millimetres from Sunday night into Monday.

Ice appears to drip from a spruce tree in Scarborough. Toronto is under rainfall and freezing rain warnings after the city endured a wintry mix of weather on Saturday that included snow and ice pellets. (Muriel Draaisma/CBC) The weather agency also issued a wind warning for Toronto Sunday afternoon, warning of strong winds in the region and severe winds near the city's lakeshore.

"The intense low pressure system which has been affecting southern Ontario continues to generate high winds funnelling along the Lake Ontario shoreline out of the northeast," the weather agency said.

"More strong winds gusts up to 100 km/h are now anticipated until after midnight along the Toronto shoreline especially affecting Toronto Island where trees have fallen."

Environment Canada is reporting that winds at Billy Bishop airport saw easterly wind gusts of 96 km/h at 8:28 p.m.

Stay off roads if you can

Toronto police are calling for cyclists and pedestrians to stay clear of the roads if possible, until the storm passes.

Const. Allyson Douglas-Cook, spokesperson for the Toronto Police Service, said vehicles have been spinning out, hitting other vehicles, crashing into poles and guard rails as drivers have lost control.

Officers were very busy on Saturday night after a string of collisions.

The icy weather has made it particularly difficult for some vehicles on the road. (Muriel Draaisma/CBC) "Thankfully, this morning hasn't been as crazy per se as last night was. Last night, we had numerous collisions reported throughout the city," she said.

"We're stressing the importance of not leaving home unless you absolutely have to and try to stay off the roadways."

Douglas-Cook urged drivers to slow down, allow extra time to reach destinations and ensure following distances are more than adequate.

City 'comfortable' with level of plowing

Barbara Gray, general manager of Toronto's transportation services division, says there are 80 salt trucks operating in the city. Thirty of those vehicles have plows, she added. During peak winter weeks, the city usually has access to some 200 salt trucks.

"We are comfortable with the level of equipment we have on the roads," Gray told reporters.

Gray says plows are focusing on main roads, such as "high priority" arterial routes, ramps, hills and bridges, but some roads won't be plowed because they include catch basins.

A snow plow clears a sidewalk in Kitchener, Ont., on Sunday. (Gary Graves/CBC) If those basins become clogged with snow and ice, it could lead to increased flooding overnight and on Monday.

Mayor John Tory sought to reassure Toronto residents that plowing that needs to be done is being completed in Toronto.

"A lot of people have raised questions about the plowing. The plowing has been done on the expressways in accordance with the city's standards regarding weather events," Tory said.

The mayor's event to celebrate the Toronto Maple Leafs and Toronto Raptors at City Hall Monday morning was cancelled Sunday evening because of the ongoing storm.

Flights cancelled at Pearson, Billy Bishop

These are the conditions for staff working outside today. Icy conditions combined with the presence of multiple vehicles and large aircraft in motion mean that safety is always our top priority. Thank you to all our airport workers keeping passengers safe. <a href="https://t.co/sdWDlF6oZk">pic.twitter.com/sdWDlF6oZk</a> —@TorontoPearson Toronto's Pearson International Airport is urging travellers to check their flight status before they leave home and to arrive early at the airport. More than 330 departing flights and over 350 arriving flights have been cancelled as of about 8 p.m. Sunday.

"We're working closely with our airline partners to keep traffic moving and to make sure that workers outside are kept safe in these weather conditions," Robin Smith, spokesperson for the Greater Toronto Airports Authority, told CBC Toronto Sunday. "Our central de-icing facility is still fully staffed and there are additional staff in the terminals to help keep passengers informed throughout the day."

At Billy Bishop Airport, all flights and ferry service to the airport have been cancelled. The airport only received one flight on Sunday, but it remains open for those who need to rebook flights.

April 15: Due to weather conditions all remaining flights from <a href="https://twitter.com/hashtag/YTZ?src=hash&ref_src=twsrc%5Etfw">#YTZ</a> have been cancelled for today and ferry operations have ceased. The airport remains open for those who need to rebook flights. —@BBishopAirport

Hours of freezing rain

Geoff Coulson, a weather preparedness meteorologist for Environment Canada based in Toronto, said the Greater Toronto Area is grappling with a second wet and wintry day.

Coulson described the spring storm as not typical for this time of year.

"This is very unusual. To get this much freezing rain, this late into the spring, is not something I can recall happening over the last number of decades here in the Greater Toronto Area."

Previous Next Coulson estimates the freezing rain and ice pellets could produce an ice buildup of about 10 millimetres or more.

Flooding possible in some areas

Flooding in low-lying areas is possible on Sunday, Environment Canada said in its rainfall warning. It urged people to keep children and pets away from creeks and river banks.

According to the forecast, rain is expected to continue into Monday but it is likely to be lighter.

Coulson said the temperature is expected to be about 4 C by Monday morning, then reach a daytime high of 9 C.

Ice pellets gather on a car hood. (Kate Bueckert/CBC) "The rain should be stopping tomorrow as temperatures getting back to well above freezing."

Universities expected to be open Monday

York University, Ryerson University and the University of Toronto all say that they expect to be open tomorrow morning and all exams will proceed as scheduled.

The Toronto District School Board, Toronto Catholic District School Board, Peel District School Board and the Durham District School Board are expected to announce any school closures or bus cancellations Monday morning.