More than 170,000 of them were in areas across Long Beach, Atlantic Beach, Fire Island and Rockaway Peninsula.
But Con Edison said it had restored power to more than 90% of its customers, leaving 12,500 households in Queens, 10,400 in Brooklyn, 3,500 in Staten Island and 4,200 in the Bronx without electricity as the cold weather moved in.
About 39,000 customers in Westchester County also remained in the dark.
By Wednesday, New Jersey's largest power provider, PSE&G, said it had restored power to about 89% of its storm-hit customers, leaving more than 190,000 still in the dark.
"It is like a war zone down there," New Jersey Gov. Chris Christie said, referring to places such as Ocean County's Mantoloking, where flooding and fires wiped out large sections of the town last week.
At least 20 homes burned to the ground there, mirroring an incident in Breezy Point, a Queens neighborhood where a cluster of more than 100 houses caught fire during the storm.
"We don't know what to expect for the flooding situation as the shorelines have been changed," Christie said. "For many of them, the dunes are gone. So, moderate flooding under normal conditions becomes major in these conditions."
More than three-fourths of New Jersey's school systems were operating Wednesday and 1,728 public schools were open in New York.
Elsewhere, there were signs of the region rebounding.
The PATH train between New Jersey and New York resumed limited service under the Hudson River on Tuesday, after being shut down ahead of the storm.
Commuter traffic reopened early Wednesday in the Holland Tunnel, where about 91,000 vehicles typically pass under the Hudson River between Manhattan and Jersey City, New Jersey.
Air travel continued to be affected. Authorities advised air travelers to check with their carriers ahead of the storm.
"Airlines serving the Port Authority's major airports -- Newark Liberty International, John F. Kennedy International and LaGuardia -- have canceled all or a significant number of their flights beginning at noon today and continuing through early tomorrow," the Port Authority of New York and New Jersey said Wednesday in a statement.
United Airlines, the world's largest air carrier, suspended most New York City service starting at noon, while American Airlines was expected to shut down in New York at 3 p.m. and stop flights to and from Philadelphia by noon.
More than 1,700 flights in the New York region were canceled on Tuesday and Wednesday, said FlightAware, which describes itself "the most popular flight tracking service in the country."