New York City area airports had almost 6,000 flights canceled or delayed because of last weekend’s historic blizzard, according to an analysis by an airport advocacy group.

The group, Global Gateway Alliance, looked at flight disruptions at airports across the country to see the impact of the storm. Even those thousands of miles away were affected by the weather on the East Coast, with the Los Angeles International Airport hit with almost 1,100 delays and cancellations, according to the analysis.

JFK Airport suffered the most delays and cancellations of all the airports in the U.S., with at 2,140 affected flights. LaGuardia had 1,714, while Newark had almost 2,000.

Airports at or near Washington, D.C., which was battered badly by the blizzard, had more than 3,700 flights canceled or delayed.

The data used by the Global Gateway Alliance was from the website FlightStats.com, which compiled it from the FAA.

A representative for the Port Authority did not immediately comment on the data.

A spokeswoman for Global Gateway Alliance said air traffic technology needs to be upgraded to help the airports recover more quickly from extreme weather. More amenities for riders trying to cope with severe weather delays, such as sleeping pods, fitness centers, and unlimited free Wi-Fi, would also be beneficial, she said.

“Last weekend, the Port Authority and the airlines took the necessary measures to keep passengers safe in the midst of the city’s second-largest snowfall,” said the group’s executive director in a statement, Joe Sitt.

“But we have to remain focused on modernizing our airports, so we finally have both the 21st century air traffic technology needed to recover faster from these weather events and the amenities that passengers look for during hours- or days-long waits.”