Some 125,000 Hydro-Québec customers are without power after freezing rain and strong winds sent tree branches crashing onto power lines and caused havoc on the roads.
The largest number of affected customers are in the Montérégie region southeast of Montreal, where some 113 outages have left almost 105,000 people in the dark as of 11 a.m. Sunday.
Environment Canada issued snowfall and winter storm watches for much of the south and east of the province, from the Laurentians north of Montreal to the tip of Gaspésie.
Meteorologist Simon Legault says between 15 and 25 centimetres of snow had already fallen on the Quebec City region on Sunday morning, with another 15 or so expected to come.
Blowing snow and difficult driving conditions caused the closure of several roads Sunday morning, including Highway 20, which was closed in both directions between Lévis and Montmagny southeast of Quebec City.
Bruno Lacombe of the provincial transportation department warned of icy conditions, snowy roads and reduced visibility in areas surrounding Montreal and Quebec City.