The storm dumped up to 60cm of snow in parts of the metropolitan northeast as accumulations from an earlier snowfall had just melted away - except for grey mountainous piles in parking lots and along the side of roads.
Officials declared emergencies from Delaware to Massachusetts, and hundreds of thousands of people grappled with power failure from downed electrical lines.
Even as the snow moved northward and tapered off in other areas, the National Weather Service said it is tracking another storm that could bring more snow to the region later this week.
The weather service referred to Monday's storm as a "classic bomb cyclone/nor'easter off the Northeast coast".
A bomb cyclone happens when a storm's pressure falls by a certain amount within a 24-hour period, occurring mainly in the fall and winter when frigid Arctic air can reach the south and clash with warmer temperatures.
New York City and Boston cancelled public school classes for Monday, while Philadelphia switched to online learning.
New York Mayor Zohran Mamdani called it the "first old-school snow day since 2019". But class would be back in person on Tuesday, he said.
He went on X to encourage people to sign up for emergency snow shovelling work "as we get through this historic storm".
In Lower Manhattan, snow shovellers appeared to outnumber commuting office workers, and pedestrians walked freely in streets normally blocked by morning traffic.
"It's very quiet, except for the howling winds," said Luis Valez, a concierge at a residential tower just off Wall Street, as he cleared the footpath.
Karen Smith and Adele Bawden are tourists visiting New York from the United Kingdom.
"We've been dancing in Times Square this morning in the middle of the road in rush hour," Bawden said.
New York, Philadelphia and other cities, as well as several states, declared emergencies.
More than 5000 flights in and out of the United States were cancelled for Monday, according to the flight tracking website FlightAware.
Most were cancelled in New York, New Jersey and Boston. Rhode Island's T.F. Green International Airport announced Monday that it was temporarily ending all airport operations.
Public transit ground to a halt in some areas, while DoorDash suspended deliveries in New York City overnight.
Storm-related power outages plunged more than 500,000 customers into darkness along the East Coast early on Monday, including over 212,000 customers in Massachusetts and 128,000 customers in New Jersey, according to PowerOutage.us, which tracks outages nationwide.
About 10,000 customers were without power Monday morning on suburban Long Island. New York Governor Kathy Hochul said utility crews would restore power as soon as possible, but winds of 80km/h or higher could delay action.
In New York City, several subway lines reported severe delays, while the Long Island Rail Road was fully suspended until further notice.
Some Metro-North commuter trains between New York City and its suburbs were delayed by up to an hour. New Jersey Transit suspended bus and rail services "until further notice."
The weather service said strong wind gusts could cause whiteout conditions and warned of a "Potentially Historic/Destructive Storm" southeast of the Boston-Providence corridor.
"Winds like that, combined with heavy, wet snow, are a recipe for damaged trees and prolonged power outages," said Bryce Williams, a meteorologist with the weather service's Boston office.
"That's what we're most concerned with, is the combination of those extreme snow amounts with that wind."
Outreach workers meanwhile tried to coax homeless New Yorkers into shelters and warming centres.
Various landmarks and cultural institutions were closed Monday, including New York's Museum of Modern Art and the Arlington National Cemetery in Washington, DC Broadway shows were cancelled.
