MONTREAL — Roughly 55,000 clients are without power in Ontario and Quebec after severe thunderstorms on Thursday swept across Central Canada, which was already dealing with sweltering temperatures.

Environment Canada says that at the peak of the outages more than 214,000 customers were knocked off the grid in Ontario and nearly 140,000 customers were without power in Quebec.

Hydro One, Ontario’s power utility, says crews are working “as safely and quickly as possible” to fix service to about 25,000 customers after several rounds of thunderstorms since Canada Day.

While in Quebec, Audrey St-Pierre, spokesperson for Quebec’s hydro utility, says about 200 teams of workers have been dispatched to restore service to about 30,000 clients. St-Pierre says Hydro-Québec expects power to be restored to most areas by 11 p.m.

The Lanaudière region, north of Montreal, is the most affected with about 15,000 customers still without power.

Environment Canada says strong winds accompanying the thunderstorms uprooted many trees across Ontario and southern Quebec, knocking down power lines. The Montréal-Trudeau International Airport recorded wind gusts of 96 kilometres per hour.

Thursday’s storms were accompanied by record-setting temperatures in Ontario. Oshawa’s airport recorded a high of 35.2 C, beating a record set in 1931 of 33.9 C. Toronto Pearson Airport saw 36 C with a peak humidex value near 48, another record for July 1, the weather agency said.

Parts of southern Quebec including Montreal have been under heat warnings since earlier this week.

In Montreal, Friday’s high is expected to hit 32 C with a humidex value of 39. Temperatures are expected to cool slightly for the weekend and reach 28 C on Saturday and Sunday.

This report by The Canadian Press was first published July 3, 2026.

Charlotte Glorieux, The Canadian Press