A severe thunderstorm on Wednesday 29 July caused Denver International Airport disruptions on a scale that placed the hub top of the global rankings for both departure and arrival delays, after the Federal Aviation Administration (FAA) issued a ground stop that temporarily halted all flights at the airport. According to FlightAware, the day’s weather event contributed to 7,699 delays within, into, or out of the United States, alongside 559 cancelled flights nationwide.
Ground Stop Triggers Hour-Plus Delays at Denver
Heavy rain and flash flood warnings across the Denver area arrived at the airport in the mid-afternoon, prompting the FAA to issue a ground stop that brought departures and arrivals to a halt. A ground delay programme followed, producing average delays of more than an hour. CBS News Colorado reported that the ground stop was expected to lift by 5 p.m., with officials placing the probability of an extension at approximately 30%.
Denver International (DEN) recorded 521 delays on departing flights and 456 on arrivals, making it the most disrupted airport worldwide for the day. LaGuardia Airport was second among domestic hubs for departure delay rate at 46%, while DEN’s own rate reached 47% of total departure volume. Chicago O’Hare International Airport and Dallas-Fort Worth International Airport each recorded more than 330 departure delays, at 22% and 29% respectively, with Newark Liberty International Airport rounding out the top five at 265 delays and a 42% rate.
As DEN’s largest carrier, United Airlines bore the heaviest operational burden. The carrier recorded 20 cancellations and 327 delays at Denver alone, and 108 United flights were cancelled in total across the network, driven by compounding disruptions at its other major hubs, Newark Liberty International Airport and Chicago O’Hare International Airport.
Denver International Airport Disruptions: The Passenger Experience
The operational picture translated into lengthy ordeals for travellers on the ground and in the air. One United customer, identified as Clyde on X, documented the sequence of events on a flight bound for Denver. After a normal boarding process, passengers were instructed to deplane for what was initially described as an unknown reason. The captain subsequently told passengers they needed to re-board because of an air traffic control input error.
‘After boarding again, we sat for about an hour with no updates before learning that weather in Denver was preventing us from landing. We remained on the plane without air conditioning, and after more than three hours on the ground, the pilot finally announced we were cleared for takeoff, but we still had to wait for the baggage to be loaded,’ Clyde wrote. The flight was then rerouted over the Rocky Mountains, adding close to an hour to the journey. On landing at DEN, the aircraft had no gate available, leaving passengers on the tarmac with a connection boarding in 35 minutes. Clyde’s final update placed arrival time at 10:16 p.m. against a scheduled departure of 7:35 p.m.
United responded to the post requesting flight details. Denver International Airport also addressed passengers directly on X, advising: ‘We are experiencing heavier than usual traffic at our security checkpoints. Expect longer lines. Give yourself extra time to get through security this morning and check http://flydenver.com for current wait times.’
Nationwide Picture: Newark, Boston and New York Also Hit
Wednesday’s disruptions were not confined to Colorado. Flights serving the New York, New Jersey and Boston corridors all saw elevated cancellation rates. Newark Liberty International Airport recorded 63 cancelled departures, the highest of any airport in the country for the day. Boston Logan International Airport and LaGuardia Airport each logged 40 departure cancellations.
The Denver ground stop came one day after the FAA halted flights at 13 major airports, and two days after an American Airlines IT outage compounded an already difficult week for network operations across the country.
Looking ahead, disruption levels were reported as low in early Thursday morning checks. Boston Logan has the most scheduled cancellations for Thursday at 14, while Delta leads among carriers at 21 planned cancellations. The FAA has indicated it may issue further ground stops if weather conditions develop, with the potential for additional Denver International Airport disruptions and broader network knock-on effects if storms track over major hub corridors again.
