Tens of thousands of Ontario residents are still without power following a major windstorm, and parts of the province remain under warning for more high winds.

By late evening, roughly 70,000 customers were waiting for their electricity to be restored. At the peak of the outage on Sunday, 235,000 customers found themselves in the dark.

"We're going in the right direction," spokesperson Danielle Gauvin told ctvtoronto.ca on Monday.

But the company warns power may not be restored for customers in the least-accessible areas until Friday -- and that a new weather system in the Georgian Bay area could result in additional outages.

In southwestern Ontario, several communities including Orillia and Waterloo are under high wind warnings.

On Sunday, wind gusts of up to 100 kilometres per hour -- almost 120 km/h in one location -- swept across the province.

"We recognize that yesterday's storm has had a significant impact on our customers during the holiday season," said Myles D'Arcey, the company's senior vice president of customer operations, in a news release.

"We are mobilizing every available resource to help get power restored to our customers and we thank them for their continued patience during this challenging time."

Hydro One said it has 1,300 workers, both its own employees and from 22 local utilities, out working to restore electricity. They will work into the evening, Gauvin said.

Ten helicopters, which couldn't fly Sunday because of the winds, are out on Monday and will work until dark, she said.

Here are areas where outages of more than 1,000 customers remained as of 10 p.m.:

  • Bancroft - 14,500
  • Huntsville - 12,900
  • Parry Sound - 11,900
  • Bracebridge - 9,900
  • Manitoulin - 4,500
  • Minden - 4,500
  • Cobden - 3,900
  • Penetang - 3,500
  • Nipissing - 2,100
  • Fenelon Falls - 1,800
  • Tweed - 1,400
  • Owen Sound - 1,300
  • Perth - 1,000

Gauvin said headway has been made in places such as Parry Sound and Cobden.

She said the repair of one major line can reconnect more than 1,000 people to the grid at once, but individual homes and streets are more time-consuming.

The utility is watching the winds for Monday night, she said.

According to Environment Canada, wind speeds in Barrie were below 20 km/h on Monday morning, but they could gust to 90 km/h overnight before slowing again.

Toronto Hydro reported at noon that all its customers now had their electricity back.

Winds speeds at Pearson International Airport had died down to about 22 km/h on Monday morning after sustaining speeds of 70 km/h on Sunday.

On Monday morning, crews were chopping up fallen trees in neighbourhoods such as Little Italy, where a tree estimated to weigh more than 5,400 kilograms fell on a garage.

"We heard a big bang and the tree came down. It was pretty freaky," Frank Lopes, who was in the garage, told CTV Toronto.

With a report from CTV Toronto's Dana Levenson