Hundreds of thousands of people were without power across Central Canada on Saturday morning following a windstorm that downed trees and power lines and left two people dead.

Environment Canada said wind gusted at close to 120 kilometres per hour on Friday in the wake of a cold front that moved across Ontario and Quebec.

Hydro One, Ontario's largest power utility, was reporting more than 200,000 customers affected by outages on Saturday morning, though the number dropped later on in the day. Toronto Hydro said at one point 68,000 customers were in the dark, though that number also fell.

The city's utility noted Saturday that outages could last for an extended period of time, adding that this was the third major storm to pummel the region in the spring season.

"We're in a significant emergency state and are dealing with the after-effects of a major windstorm," Toronto Hydro tweeted.

"Damage is severe and some outages will be lengthy."

In Quebec, more than 195,000 people were in the dark on Saturday morning after the storm gusted through at speeds reaching 100 km/h.

Hydro Quebec asked customers for patience as its crews worked to clear the downed trees and branches that damaged its grid in several areas of the province.

The most affected region was the Monteregie in southern Quebec, where 53,000 people were still in the dark as of 8 a.m.

In Montreal, downed branches blocked several roads but the utility said no major damage was reported.

But most of the damage came on Friday, when police west of Toronto said two people died as a result of the winds.

Halton Regional Police said a tree fell on two men who were "working on tree servicing" on Friday afternoon in Milton, Ont., killing one and injuring the other.

And in Hamilton, police said a man who had been trying to clear downed power lines was found "in contact with live wires" on a road and died soon after emergency services arrived on Friday evening.