Tens of thousands of people were left without power after a late winter storm swept eastwards across with heavy snowfall and strong winds.
Ontario and Quebec were among the areas buffeted by the blizzards that knocked out electricity and disrupted travel.
In the US, crews were working overtime to clear up after a huge storm hit parts of the Midwest at the weekend.
Among the worst-hit areas was Ohio, with the capita, Columbus, seeing a record 20 inches (50cm) of snow.
Four people were reported to have died in Ohio while shovelling snow. Another person was said to have died in a traffic accident caused by the bad weather.
Two deaths were blamed on the storm in New York state and one in Tennessee, the Associated Press reported.
The snow was preceded by freezing rain, ice and sleet that swept an area from eastern Kentucky into New York state.
The central United States and parts of Canada have suffered one of their worst seasons of winter weather in years.
In Canada, air traffic via Toronto, Montreal and Ottawa was disrupted by the same storm system that hit Ohio.
Over the weekend, blizzards and high winds swept over Ontario and Quebec, temporarily knocking out electricity to some 80,000 homes and businesses.
Road and air transport was severely disrupted.
By Sunday, the storm was moving into Canada’s Atlantic region.
A young boy was reported to have died in New Brunswick, which saw up to 40cm of snow.
“As soon as the snow from one storm turns brown, more snow arrives,” Environment Canada meteorologist Guy Roussel told the Globe and Mail newspaper.
“People in New Brunswick are fed up with winter. They’re buried in snow. They’re just waiting for spring.”
Forecasters said the storm, which was at its fiercest over Ontario and Quebec, was gradually losing strength.