More than 100,000 people from Virginia to Connecticut were without electricity as up to 45 centimetres of snow coated the region.
Flakes of snow were reported as far south as Tennessee.
New York's busy La Guardia airport, Newark International in New Jersey and Reagan National in Washington DC were closed, the Federal Aviation Administraion said, as well as a number of other smaller regional airports.
Other key airports have cancelled hundreds of flights, according to media reports.
A blizzard warning was issued for the metropolitan New York City area and much of the northeast.
New York Mayor Michael Bloomberg urged people to stay home, saying "This is a dangerous storm."
By late morning on Sunday, about 56cm of snow had fallen in New York City's Central Park, the city's second heaviest snowfall on record, prompting some New Yorkers to bring out their skis.
The National Weather Service also gave flood warnings for the Massachusetts-Rhode Island coastline.
Visibility was low on roads around Boston as snow continued to fall with winds up to 56 kph on the Massachusetts coast.
But with ample warning of the storm, authorities were able to keep many main highways open across the northeast.