Drones and Weather Balloon Disrupt Hundreds of Flights at San Diego

San Diego International Airport faced hours of disruption on Friday, September 4, after pilots reported both a high-altitude weather balloon and multiple drones near the airfield, triggering ground stops, long delays and diversions affecting hundreds of travelers across the United States.

Reports of Balloon and Drones Prompt Immediate Flight Restrictions

Publicly available flight tracking data and passenger accounts indicate that operations at San Diego International Airport were repeatedly interrupted after sightings of an apparent weather balloon at high altitude and drones operating much closer to the runway and control tower. Social media posts from passengers at the airport and on inbound flights describe departures being halted and arriving aircraft placed in holding patterns or diverted to other airports, including Los Angeles International.

Discussion threads on airline and local forums describe at least one drone reportedly hovering close to the airport control tower area, with additional reports of a second drone appearing soon afterward. Separate posts from residents in the city reference a shiny or silver object high over San Diego that users identified as a long-range weather balloon that had been tracked across the Pacific. Aviation enthusiasts tracking flights to San Diego shared screenshots showing multiple inbound aircraft placed in extended holding or rerouted away from the region.

While detailed official tallies of affected flights were not immediately available, the pattern of widespread delays, diversions and rolling ground stops described online suggests that hundreds of individual flight segments were impacted across multiple airlines. Passengers posting from cities as distant as Boston and other hubs reported their San Diego-bound departures being held at the gate while the situation unfolded.

Ground Stops and Cascading Delays Across the Network

Information published through the Federal Aviation Administration’s air traffic status tools indicates that San Diego International was already managing a high volume of traffic during the afternoon, with a traffic management program in effect and average arrival delays building. Separate airport delay reports in the days leading up to the incident show elevated congestion in Southern California airspace, meaning any additional airspace restrictions were likely to ripple quickly through the system.

Accounts from travelers and pilots on aviation forums describe a ground stop at San Diego lasting several hours, during which no departures were permitted while air traffic controllers worked around the reported drone activity. One passenger at the airport reported delays exceeding three hours, while another described a pilot announcement that drones had been observed flying over or near the airfield, forcing a temporary halt to takeoffs.

Because San Diego International operates with a single primary runway on a compact footprint near downtown, even short disruptions can generate significant queues of aircraft waiting to depart or land. Once a ground stop is lifted, recovery can take hours as airlines reposition aircraft, crews and passengers, and as connecting flights are rescheduled nationwide. Flight status boards on airline websites on Friday afternoon showed large clusters of late arrivals and departures into and out of San Diego, consistent with a protracted operational interruption.

Passenger Experience: Long Waits, Diversions and Uncertainty

Travelers caught in the disruption reported a mix of extended gate holds, in-flight delays and unexpected diversions. Several passengers posting on airline-specific forums said they were seated on aircraft at the gate in San Diego with limited information, told only that drone activity near the airport was preventing their departure. Others reported that flights already en route to San Diego were diverted, with at least one traveler describing a family member’s plane being redirected to Los Angeles because drones were reported near the arrival path.

Some passengers posted that pilots referenced a drone hovering tens of feet above the airport’s tower and that a second drone had later been spotted, while others said they were informed that a helicopter was searching the area. A number of travelers expressed concern about missed connections and overnight disruptions, especially on evening departures that were rescheduled repeatedly as air traffic controllers adjusted spacing and arrival rates into an already congested airspace.

In online discussions, local residents watching flight patterns in real time remarked that the combination of a high-altitude balloon and closer-range drones had created an unusually complex situation. While the balloon itself appeared to be passing over at a much higher altitude, reports indicated that its presence added to the caution around the airport at a time when low-level drone sightings were already constraining operations.

Safety Concerns Over Drones Near Airports

Published guidance from federal and regional agencies stresses that small unmanned aircraft systems, including consumer drones, must not operate close to commercial airports or inside controlled airspace without explicit authorization. In San Diego County, emergency and aviation planning documents highlight temporary drone restrictions as a key safety measure around critical infrastructure and busy air corridors, reflecting concerns about the risk even a small unmanned aircraft can pose to passenger jets on approach or departure.

Nationwide, aviation safety studies have flagged the potential hazards from drones operating near runways, including the danger of a collision with an aircraft’s windshield or engines, or creating a distraction for flight crews during critical phases of flight. As commercial drone use and recreational flying have grown, temporary airspace closures and ground stops linked to unmanned aircraft sightings have become more frequent at major airports, occasionally resulting in widespread disruption when activity is reported close to an active runway or control tower.

San Diego International, which serves as the primary air gateway for the metropolitan area and routinely handles tens of thousands of passengers per day, is particularly sensitive to any airspace incursions because of its constrained footprint and dense urban surroundings. Any object reported near its single main runway, whether a drone or other unidentified device, can quickly reduce capacity and force controllers to suspend or significantly slow operations.

Ongoing Monitoring as Operations Normalize

By late Friday afternoon, passenger posts and airline updates indicated that departures from San Diego were resuming, although many flights remained significantly delayed and some downstream disruptions were expected to carry into the evening. Travelers booked to or from San Diego over the weekend were encouraged by airlines and airport information channels to monitor their flight status closely and allow extra time for connections, because aircraft and crews remained out of position following the earlier stoppages.

Real-time status information from federal air traffic systems on Saturday showed San Diego operating without a formal ground stop but still experiencing moderate arrival delays linked to volume. Notices to air missions for the broader San Diego area also referenced scheduled unmanned aircraft activity over the coming days, underscoring that drone operations in the region are expected to continue under tightly controlled conditions.

For now, publicly available coverage suggests that the combination of a transiting weather balloon and low-flying drones created a rare convergence of factors over one of the country’s busiest single-runway airports, leading to cascading delays for travelers across multiple airlines and regions. As airlines work through residual disruptions, San Diego’s experience adds to a growing list of incidents demonstrating how even small unmanned aircraft, when spotted near critical airspace, can bring a modern airport’s tightly choreographed schedule to a halt.

FAA real-time airport status for San Diego International (SAN)

Current NOTAMs for KSAN / San Diego International Airport

San Diego local aviation and travel discussion threads

United Airlines passenger reports on San Diego drone ground stop

Southwest Airlines passenger reports on San Diego drone ground stop