More than 40,000 people were without power and one busy Toronto airport had to shut down on Sunday as southern and central Ontario were battered by another day of freezing rain and ice pellets.

Environment Canada issued weather warnings for the entirety of the region for the second day in a row, advising that strong winds could exacerbate already dangerous conditions.

Toronto's downtown Billy Bishop airport cancelled all departing flights and only received one arrival all day on Sunday, while more than 600 flights were cancelled at Pearson International Airport.

Dozens of flights were also cancelled or delayed at Ottawa International Airport.

Meantime, provincial power utility Hydro One said extra crews were working to address power outages, with fallen trees and broken poles causing most of the issues.

The mixture of freezing rain and ice pellets made for nasty road conditions, particularly in the Greater Toronto Area, said Chris Scott, chief meteorologist with The Weather Network.

"These ice pellets have acted like very dense snow on the road," he said. "That's created treacherous driving conditions across much of southern Ontario, but especially in the GTA."

Ontario Provincial Police said there were roughly 750 crashes on highways surrounding Toronto on Saturday, and there had been around 700 more by Sunday evening. None of the crashes were fatal.

Wind warnings were also issued, with gusts up to 90 kilometres per hour forecast for the Hamilton area -- strong enough to cause property damage and further power outages.

Scott said areas near Lake Erie were hit with the most freezing rain and ice pellets, while the region around St. Thomas, Ont., had the most power outages.

"It's rare to get such a winter storm this late in the season," said Scott, noting that southern Ontario hasn't seen such an intense ice storm in April in over a decade.

Environment Canada said the freezing rain and ice pellets would change to rain later Sunday as temperatures rose, starting in the western part of the region and moving east.