A major snow storm has hit eastern Canada and north-eastern areas of the US, killing at least two people and causing major disruption to air travel.
Around 40cm (16in) of snow fell around Toronto, Ottawa and Montreal, causing what Environment Canada described as "dangerous winter weather conditions".
Freezing rain, snow storms and high winds also affected several states in New England and the Great Lakes region.
Airports across Canada and the US were forced to cancel hundreds of flights.
More than 200 flights were cancelled and many more delayed at Chicago's O'Hare International Airport alone.
The snowstorm which had earlier hit the Midwestern US brought blizzards, hail, freezing rain and high winds to Ontario, Quebec and the Atlantic provinces of Canada late on Saturday and throughout Sunday.
In Toronto and Montreal, heavy snow combined with winds gusting up to 70km/h (45 mph) caused whiteout conditions that led to several people accidentally driving off icy motorways, transport officials said.
Some people were able to enjoy the exceptional winter weather
CTV News reported that one woman was killed near London, Ontario, when her vehicle was hit by a snow plough after she had pulled over to fix a windshield wiper.
"It's a big one, a dangerous one," Environment Canada climatologist Dave Phillips told CTV, adding that more heavy snow was expected.
"Just because you have this one storm doesn't mean we're into the winter from hell, but my gosh, it's certainly started that way."
Slippery roads in the US were blamed for the deaths of a 24-year-old Michigan woman and a 51-year-old woman in Wisconsin earlier on Sunday.
Parts of New York State received around 30cm (12 in) of snow, while 25cm (10 in) fell across Maine, New Hampshire, Vermont, Massachusetts, and Rhode Island.
Forecasters said high winds would continue throughout the evening and that parts of northern New England might receive 45cm (18 in) in total.
Around 160,000 customers were left without electricity in parts of Pennsylvania on Sunday after heavy snow damaged power lines.
The snowfall comes less than a week after an ice storm claimed 38 lives in the Midwest, most of them in road accidents. Tens of thousands of people in the affected areas of Oklahoma, Kansas and Missouri still have no electricity.
WINTER CHILL ACROSS NORTH AMERICA: 16 DECEMBER, 1800 GMT