US flight cancellations from thunderstorms pushed past 1,000 on Thursday 9 July as the Federal Aviation Administration issued ground stops at multiple major airports, triggering one of the most disruptive single days of the summer season for domestic and transatlantic operations.
According to FlightAware, there were 1,014 cancellations within, into, or out of the United States on Thursday. Delays compounded the picture sharply: 9,249 flights were delayed across the same network on the same day.
Ground Stops Spread Across New York, Washington and Denver
The FAA issued ground stops at some of the country’s busiest hubs as thunderstorms swept the East Coast. Airports affected on 9 July included LaGuardia (LGA), Newark Liberty International (EWR), John F. Kennedy International (JFK), Ronald Reagan Washington National, Washington Dulles International, Baltimore/Washington International Thurgood Marshall, and Denver International. Boston Logan International was placed under a ground delay. Philadelphia International faced both a ground stop and a ground delay.
Flash flood warnings were issued across New York City and New Jersey, compressing airspace and extending ground stop durations. LaGuardia recorded the most departure cancellations of any airport worldwide at 121, and led all US airports for arrival cancellations at 106. JFK and Newark Liberty each saw more than 100 cancelled flights.
Hartsfield-Jackson Atlanta International, the key hub for Delta Air Lines, recorded the most delayed departures among US airports at 506, despite no ground stop being issued there. Delays were also elevated at Denver International, Chicago O’Hare International and Dallas-Fort Worth International.
US Flight Cancellations From Thunderstorms: The Carrier Breakdown
Among the major carriers and their regional affiliates, Republic recorded the highest cancellation count at 237. Endeavor Air, operating for Delta, followed at 141, while PSA Airlines, operating for American, cancelled 96 flights. Southwest Airlines cancelled 86 flights, Delta Air Lines 69, JetBlue 61, United Airlines 48, and American Airlines 37.
The scale of disruption over the course of the day was considerably wider than the end-of-day FlightAware figure alone captures. The Hill reported that 3,573 flights destined within, into, or out of the United States had been cancelled as of 2:00 p.m. EDT on 9 July, reflecting the cumulative churn of cancellations, rebookings and re-cancellations as the storm system moved through during the afternoon peak.
Flexible Rebooking Offers Extended by Delta and United
Both Delta Air Lines and United Airlines moved quickly to offer flexible rebooking to affected passengers. Delta’s waiver covers flights on 9 and 10 July from its major New York-area hubs: Newark (EWR), JFK, LaGuardia (LGA) and White Plains (HPN).
United’s rebooking offer extends across a broader set of East Coast hubs, covering Baltimore (BWI), Washington Reagan (DCA), Newark/New York (EWR), Washington Dulles (IAD), JFK, LaGuardia (LGA) and Philadelphia (PHL). Under United’s terms, change fees and fare differences are waived provided passengers rebook by 12 July 2026 in the same cabin and to the same cities.
Disruption Carries Into Friday
The disruption did not clear overnight. As of early Friday morning on 10 July, 197 flights within, into, or out of the United States were already cancelled. Delta had 32 cancelled flights and United had 22, both running above their usual baseline. Cancellation rates at LaGuardia and JFK remained elevated, consistent with the pattern of the preceding days.
Thursday’s disruption was not isolated. The week had already seen US cancellations exceed 1,000 on the Monday, and United faced two separate FAA ground stops at Denver International on the Wednesday. Denver and the East Coast hubs then carried the pressure through into Thursday’s storm activity.
With thunderstorm warnings remaining in effect for Friday, the FAA had not ruled out further ground stops as the afternoon weather window developed. United’s rebooking deadline of 12 July gives passengers until Saturday to rearrange travel from the affected East Coast markets.
