Major carriers such as American Airlines, United and Delta cancelled all flights into and out of three area airports in New York, the nation's busiest airspace. According to the flight-tracking service FlightAware, nearly 10,000 flights had been cancelled for Monday and Tuesday, almost all related to the storm.
Delays rippled across the U.S., affecting travellers in cities such as San Francisco to Chicago. Disruptions spread to Europe and Asia, where airlines cancelled or delayed flights to New York and Washington from cities that are major travel hubs including London, Paris, Tokyo and Hong Kong.
About one-quarter of all U.S. flights travel in or out of New York airports each day. So cancellations here can dramatically impact travel in other cities.
Businessman Alan Shrem was trying to return home to Boca Raton, Fla. His Monday morning Cathay Pacific flight from Hong Kong to New York's Kennedy airport was cancelled.
He learned he could be stuck in Hong Kong for nearly a week because the next available seat was Nov. 4. He was put on a waiting list for seats that could become available earlier.
"They just say: Yeah, it's a pretty big waiting list," said Shrem, throwing up his hands. In the meantime, he'll have to fork out $400 a night to continue staying at a nearby hotel. The airline won't pay for accommodation for stranded passengers if delays are weather related.
Forecasters say Hurricane Sandy is about 310 miles (505 kilometres) southeast of New York City, and the centre of the storm is expected to be near the mid-Atlantic coast on Monday night. The National Hurricane Center said early Monday that the storm has top sustained winds of 85 mph (140 kph), with higher gusts. Sandy is on track to collide with a wintry storm moving in from the west and cold air streaming down from the Arctic.
Airports in the metropolitan New York City area are open, but air carriers are not operating.
The Port Authority of New York and New Jersey said Monday that travellers shouldn't even try to go to Kennedy, Newark Liberty, LaGuardia and Stewart airports
Air travel in the Northeast started getting complicated on Sunday, when passengers were reporting multi-hour wait times at airline call centres.
Eileen Merberg, 50, was booked on a United flight from her home in Rochester, N.Y. to New Orleans, connecting at Washington D.C.'s Dulles airport.
She received an email saying the Washington flight was cancelled. United rebooked her first on a flight through Newark and, when that flight was also cancelled, on another flight through Chicago.
By that point, she already had told the higher education conference that she was scheduled to speak at that she wouldn't be coming. She tried to cancel her flight over the phone. After two lengthy waits — her cellphone battery ran out during the first one — she just hung up.
JetBlue Airways Corp. expects its cancellations from Sunday through Tuesday to total about 1,200. The airline has hubs at Kennedy airport and Boston's Logan. Rob Maruster, chief operating officer of JetBlue, hopes to resume New York flights on Wednesday morning. But he's worried about flooding of JFK's runways since they are all basically at sea level and near bodies of water.
Delta Air Lines Inc. has cancelled 2,100 flights over the three days. American Airlines has scrapped 1,000 flights, including 260 on regional affiliate American Eagle.
International travellers would have to wait to get to the East Coast of the U.S. All flights from Paris to Boston, New York, Philadelphia and Washington — a total of 14 — were cancelled. Air France has cancelled four into JFK and two departures.
Frankfurt airport cancelled 12 flights, with German carrier Lufthansa scrapping three to the Northeast and one out of Newark. British Airways had to cancel all its flights to and from New York, Newark, Baltimore, Washington DC, Boston and Philadelphia — a total of 20.
Eight flights out of Tokyo's Narita International Airport to New York, Newark and Washington were cancelled Monday.
Hong Kong's Cathay cancelled its two daily flights to New York for Monday and Tuesday and Air India said its daily flights to Newark and JFK had halted since Sunday.
South Korean flag carrier Korean Air delayed a flight scheduled to leave Incheon International Airport for JFK on Monday by 22 hours. Asiana Airlines delayed its JFK flight from Seoul by 26 hours.
Kelvin Chan in Hong Kong, Lori Hinnant in Paris, Danica Kirka in London and David Rising in Berlin contributed to this report.