A blizzard dumped record snow of 97 centimetres in parts of the US state of Connecticut as it continued blowing through Boston and the rest of New England on Saturday, DPA reported.
"We were very lucky. We avoided the worst of it," New York Mayor Michael Bloomberg said.
In neighbouring Massachusetts, snow tapered off in the afternoon after reaching around 60 centimetres, and a statewide ban on all driving was lifted after 24 hours.
Wind gusts of 120 kilometres an hour were recorded through the night at Boston's Logan airport, which was not expected to reopen before late Saturday. On Cape Cod, the hook-shaped Massachusetts peninsula jutting into the Atlantic, waves up to 6 metres high crashed onto beaches.
"This has been like a hurricane with snow," Jane Miller, a resident of Nantucket Island off the coast of Massachusetts, told dpa.
She said the island had been spared heavy snowfall, but surging tides had prompted the local government and Red Cross to open a shelter at a high school for people living near the coast who wanted to evacuate.
Coastal flooding was particularly bad along Massachusetts' southern mainland coastline, a stretch that was also hit in the October hurricane-turned-superstorm Sandy.
The US postal service suspended service in seven states.
Six deaths were blamed on the storm.
In New York state, a female pedestrian was struck by a car that skidded out of control, and a man died in a tractor rollover while clearing his driveway, media reports said. A Massachusetts 12-year-old died of carbon-monoxide poisoning when he sat in the family car to warm up after helping his father shovel snow.
Named Blizzard Nemo by the Weather Channel, a cable TV broadcaster, the storm's heavy snow and especially high winds toppled trees that caused power outages for more than 600,000 people across Massachusetts, New York, Maine, Connecticut and Rhode Island.
Some 400,000 blacked out electric customers were in Massachusetts alone, where The Boston Globe published a photo of total storm whiteout with the headline: "Blown Away."
Power outages caused a shutdown late Friday of the Pilgrim nuclear power plant in Plymouth, Massachusetts, according to a local radio station.
Areas of Connecticut appeared to have received the heaviest snowfall, ranging up to 97 centimetres in Milford and 91 centimetres in other areas, according to the National Weather Service.
The coastal town of Portland, Maine, received a record 74 centimetres of snow.
A news crew for broadcaster CNN reported that the doors of their satellite truck had frozen shut overnight on Cape Cod, requiring an hour to be opened.
Wind whipped snow drifts more than a metre high in Boston. A city worker told dpa that it was the worst storm since 1978, when a 36-hour blizzard killed 100 people in Massachusetts and neighbouring Rhode Island. In the 1978 blizzard, hundreds of cars were stranded in the snow, and some drivers froze to death along interstate highways.
More than 5,000 flights were cancelled since Friday, and at its height, the storm shut down all rail traffic from Philadelphia to Boston.
The governors of Massachusetts, Rhode Island, Connecticut, New York and Maine declared states of emergency.