Why Flights Get Cancelled

The Four Cancellation Categories

The BTS uses the same category system for cancellations as for delays. When an airline cancels a flight, it must report the primary reason. According to the U.S. Department of Transportation, this reporting requirement applies to every domestic carrier meeting DOT reporting thresholds, the same reporting system that underlies PlainFlights' database of domestic flight segments from 2020 through 2025. Understanding these categories helps you assess which risks are manageable and which are outside anyone's control. See our methodology for how these categories are validated.

• Weather cancellations: Severe weather that makes safe operations impossible, blizzards, hurricanes, severe thunderstorms, dense fog, ice. Airlines are not financially liable for weather cancellations, which is why they prefer to attribute cancellations to weather when the cause is ambiguous.
• Carrier cancellations: The airline's own failure, crew scheduling breakdowns, aircraft mechanical issues, insufficient aircraft availability, crew rest violations. These are the cancellations passengers are most entitled to compensation for.
• NAS cancellations: Air traffic control capacity constraints, ground stops, traffic management initiatives. When the FAA limits the number of planes that can operate into a congested airport, airlines cancel flights rather than create indefinitely delayed departures.
• Security cancellations: Airport evacuations, security breaches requiring re-screening, threats. Very rare, typically a fraction of a percent of all cancellations.

Airports With the Highest Cancellation Rates

Cancellation rates vary dramatically by airport, primarily driven by local weather patterns and congestion levels. The following airports consistently appear at the top of cancellation rate rankings in BTS data.

Check real-time cancellation rates for any airport on PlainFlights airport pages, based on BTS 2020-2025 data.

Which Airlines Cancel Most, and Least

Cancellation rates vary significantly by carrier, reflecting fleet age, crew scheduling practices, operational buffer, and the airports each airline dominates. Airlines with large hub operations at weather-prone airports (ORD, EWR, DFW) face structural disadvantages versus those concentrated at drier Western hubs.

Historically, ultra-low-cost carriers (Spirit, Frontier, Allegiant) have posted higher cancellation rates than legacy carriers, not purely due to weather, but because of leaner crew reserves, older fleet components, and smaller operational buffers. Legacy carriers like Delta and Alaska consistently outperform the industry average on cancellations.

Airline-level cancellation rates are visible on individual airline pages on PlainFlights. The data shows both the cancellation rate and the breakdown by cause category.

The ATC Factor: When It's Not Weather and Not the Airline

Air Traffic Control (ATC) staffing shortages became a significant and underreported cancellation driver in 2023-2024. The FAA has faced a multi-year shortage of certified controllers, particularly at high-complexity facilities like the Jacksonville (ZJX) and New York TRACON centers. When staffing falls below minimums, the FAA issues ground delays and ground stops, forcing airlines to cancel flights they can't slot into the reduced-capacity system.

ATC-driven cancellations are reported under the NAS (National Airspace System) category in BTS data. They tend to cluster in the Northeast and Southeast during the summer months when storm-related ATC rerouting compounds the staffing issues.

The Cascade Effect: One Cancellation Creates More

Most travelers don't realize that a single morning cancellation can trigger cancellations throughout an airline's schedule for the rest of the day. Airlines rotate the same aircraft through 4-6 flight legs daily. When a 7am departure is cancelled due to maintenance, the aircraft isn't available for the 10am, 1pm, or 4pm departures on the same aircraft's rotation, unless the airline repositions a spare aircraft or swaps equipment.

This cascade dynamic explains why cancellation rates spike dramatically during major weather events. A two-hour ground stop at ORD doesn't just cancel the flights during the stop, it creates aircraft and crew positioning problems that ripple through the afternoon and evening schedule. The cancellation you experience at 6pm might trace back to a weather event that ended at 10am.

Cancellation cause categories and typical share

BTS attributes every cancellation to one of four categories. Knowing the breakdown for any given airline or airport helps separate factors the carrier controls from factors imposed by weather or the National Aviation System. A carrier with a high "carrier" share has actionable operational quality issues; a carrier with a high "weather" share is operating in geographies or seasons dominated by uncontrollable disruption:

Shares approximated from BTS cancellation-cause reports (bts.gov/topics/airlines-and-airports). Actual values shift year to year, especially in years with major hurricane or winter-storm events.

Worked example: the cascade math behind a snowstorm

A major Northeast snowstorm grounds operations at LGA between 8 a.m. and 1 p.m. on a weekday. During the ground stop, roughly 200 LGA departures are cancelled outright. But because each aircraft typically operates 4-6 segments per day, those 200 cancellations leave roughly 600-1,000 downstream flights without their planned aircraft. Carriers can reposition spare aircraft and crews to cover some segments, but no carrier maintains enough spare equipment to cover full-day ripple. The result is that a five-hour weather window often produces 14-18 hours of schedule disruption, with cancellations rising through the afternoon and evening even though the underlying weather has cleared. This is the cascade math that turns a regional weather event into a system-wide reliability problem for the 24 hours that follow.

How to Reduce Your Cancellation Risk

No strategy eliminates cancellation risk, but data-backed choices meaningfully reduce it:

• Fly morning departures: The first departure of the day on any aircraft has the lowest cancellation risk. There are no prior-flight cascades to inherit. Check airline performance pages to see which carriers operate the earliest flights on your route.
• Choose carriers with low cancellation rates: Airline pages show historical cancellation rates. On comparable routes, the airline with the lower cancellation rate is almost always the better choice for reliability-sensitive travelers.
• Avoid connecting through high-cancellation airports: If your connection transits ORD in January or EWR in a winter storm warning, the odds of a connection failure are elevated. Airport data shows seasonal cancellation patterns to help you choose less risky connection points.
• Consider travel insurance for high-risk trips: Weather cancellations are legal, expected, and not compensated by airlines. For important travel (weddings, cruises, international connections), credit card travel insurance or standalone policies cover costs that airlines won't.
• Build buffer time: If your trip requires making an event by a certain time, arrive a day early. The alternative, a last-minute cancellation before a wedding or conference, is far more stressful.

Frequently Asked Questions