On September 18, 2026, the FAA held 18 airports across the United States under a total of 26 delay programs. The most affected airport was Fort Lauderdale-Hollywood International (FLL), which experienced a three-hour ground stop program due to thunderstorms.
FAA Delay Programs Across 18 Airports
The delay programs included 6 ground stop programs, which hold departures bound for an airport on the ground at their origin, and 10 ground delay programs, which meter arrivals by assigning later departure times. The remaining 10 were general arrival and departure delay notices.
Fort Lauderdale-Hollywood International (FLL) led with a ground stop program caused by thunderstorms from 19:00 to 22:00 UTC, lasting 3 hours with peak maximum delay of 0 minutes reported during our sample intervals. Miami International (MIA) and Charlotte Douglas International (CLT) also had ground stops due to thunderstorms lasting 2 hours 40 minutes and 1 hour
respectively.
Boston Logan International (BOS) experienced a lengthy ground delay program lasting 22 hours 40 minutes due to runway construction, producing a peak average delay of 136 minutes and a maximum delay of 386 minutes. San Francisco International (SFO) had a ground delay program with delays attributed to low ceilings running almost as long at 21 hours 40 minutes with peak average delay of 82 minutes.
Chicago O’Hare International (ORD) encountered a four-hour ground delay program from 00:20 to 04:20 due to ‘other’ causes with peak average delays of 129 minutes. Newark Liberty International (EWR) saw a two-hour ground delay
program caused by ‘other’ reasons with a peak maximum delay of 343 minutes.
Other airports with significant ground delay programs were Seattle-Tacoma International (SEA) for 4 hours with runway construction, Denver International (DEN) for 1 hour 40 minutes due to thunderstorms, Harry Reid International (LAS) for 3 hours 20 minutes caused by wind, and San Diego International (SAN) with 3 hours 40 minutes delay from airport volume issues.
| Airport | FAA programme | Cause | Peak average delay | In force (UTC) |
|---|---|---|---|---|
| Fort Lauderdale-Hollywood International (FLL) | Ground Stop Programs | thunderstorms | – | 19:00 to 22:00 (3 hours) |
| Miami International (MIA) | Ground Stop Programs | thunderstorms | – | 19:00 to 21:40 (2 hours 40 minutes) |
| Charlotte Douglas International (CLT) | Ground Stop Programs | thunderstorms | – | 21:00 to 22:00 (1 hour) |
| Boston Logan International (BOS) | Ground Stop Programs | low ceilings | – | 14:00 to 14:20 (20 minutes) |
| San Francisco International (SFO) | Ground Stop Programs | low ceilings | – | 18:20 to 18:20 (20 minutes) |
| Denver International (DEN) | Ground Stop Programs | thunderstorms | – | 22:40 to 22:40 (20 minutes) |
| Boston Logan International (BOS) | Ground Delay Programs | runway construction | 136 min | 00:00 to 22:40 (22 hours 40 minutes) |
| Chicago O’Hare International (ORD) | Ground Delay Programs | other | 129 min | 00:20 to 04:20 (4 hours) |
| Newark Liberty International (EWR) | Ground Delay Programs | other | 87 min | 20:40 to 22:40 (2 hours) |
| San Francisco International (SFO) | Ground Delay Programs | low ceilings | 82 min | 00:00 to 21:40 (21 hours 40 minutes) |
| Denver International (DEN) | Ground Delay Programs | thunderstorms | 51 min | 21:00 to 22:40 (1 hour 40 minutes) |
| BNA | Ground Delay Programs | other | 46 min | 20:00 to 21:40 (1 hour 40 minutes) |
| Harry Reid International (LAS) | Ground Delay Programs | wind | 42 min | 00:00 to 03:20 (3 hours 20 minutes) |
| San Diego International (SAN) | Ground Delay Programs | airport volume | 40 min | 00:00 to 03:40 (3 hours 40 minutes) |
Top Causes for Delay Programs
Runway construction was the leading cause, cited in 47 samples across airports like Boston Logan (BOS) and Seattle-Tacoma (SEA). Low ceilings caused 45 samples of delay programs, primarily impacting San Francisco International
(SFO) and Boston Logan (BOS).
Thunderstorms were the third most frequent cause with 33 samples. These weather-related delays affected multiple airports including Fort Lauderdale-Hollywood (FLL), Miami International (MIA), Charlotte Douglas (CLT), Denver International (DEN), and Ronald Reagan Washington National (DCA).
Additional causes included wind, which affected Harry Reid International (LAS) and LaGuardia (LGA), and airport volume impacting San Diego International (SAN). The FAA also cited traffic management initiatives such as “TM Initiatives:SWAP:WX” at LaGuardia and Teterboro (TEB).
Comparison to Previous Days
Compared to September 17, 2026, the number of airports affected decreased from 21 to 18, and active programs dropped from 33 to 26.
This is slightly above the recent 7-day average of 16.3 airports impacted daily. The current delay levels are not the worst in the tracking window.
Methodology. travelandtournews.com samples the FAA’s National Airspace System status feed every 20 minutes throughout the US operating day and aggregates the result. This report is built from 69 samples taken between 00:00 and 22:40 UTC on 2026-09-18. Durations are the observed window between the first and last sample in which a programme was in force, so a programme’s true length may be slightly longer than shown. Ground stops, ground delay programmes, airport closures and general
delays are all published by the FAA in real time; the daily aggregation is ours.
