Guide
Diverted flights: which airports, airlines and routes divert most
0.29% of US flights landed somewhere other than planned from September 2025 to August 2026. On Dallas-Fort Worth (DFW) to Aspen (ASE) it was 4.63%. Where diversions happen, and what one costs you.
Of the 7.05 million flights scheduled from September 2025 to August 2026, 0.29% took off and then landed somewhere other than where they were going. That is a small share, smaller than the 1.89% that were cancelled outright. On Dallas-Fort Worth (DFW) to Aspen (ASE) it was 4.63%, roughly one flight in twenty.
A diversion is the least visible failure in the data and one of the most expensive for the passenger on board. It rarely shows up in the headline figures, because a diverted flight never arrived at its scheduled gate and there is nothing to score.
How a diversion is counted
The DOT's on-time file flags every flight that landed at an airport other than its scheduled destination. A flight that turns back and lands where it started counts as a diversion in the file too. The file also records whether the aircraft eventually reached its original destination, and how late.
I took the simpler route, set out on the methodology page: diverted flights, like cancelled ones, are left out of every on-time rate and reported separately as a diversion rate, a share of all scheduled flights. The DOT's own monthly consumer report takes the other approach and counts cancelled and diverted flights as not on time. Neither is wrong, but it means an on-time percentage here is slightly kinder to a route with many diversions than the DOT's headline figure would be. The connection risk tool makes no such allowance: it treats a diverted inbound flight as a missed connection, which for the passenger it almost always is.
What happens to you when it happens
Three outcomes cover most diversions. The aircraft waits at the alternate airport for the weather to clear, refuels and continues, arriving hours late. The crew runs out of legal duty time while waiting and the continuation is cancelled, leaving passengers at an airport they never meant to visit. Or the airline gives up on the last leg and buses everyone the remaining distance, which is common when a mountain airport closes.
A diversion can also be medical or mechanical rather than weather-related. Those are spread thinly across all routes, while weather diversions cluster in specific places.
The routes
US average 0.29%
0.00%5.00%
Share of scheduled flights that landed somewhere other than their destination. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
Aspen owns the top of the list. Dallas-Fort Worth to Aspen diverted 4.63% of its flights, O'Hare to Aspen 4.49%, and Los Angeles to Aspen 4.57%. Aspen sits in a narrow valley with terrain close on three sides, a single runway, and approach minimums well above those at a flatland airport. When cloud lowers or the wind turns, aircraft cannot land, and a flight that has already come 700 or 1,000 miles has nowhere to go but an alternate.
The comparison with Denver is the telling one. All four Aspen routes are flown by SkyWest, with regional jets, on behalf of the big network carriers. Yet Denver to Aspen diverted only 1.42% of its flights and cancelled 5.11%. From Denver, 125 miles away, the airline can hold the flight on the ground until the weather is known and cancel it if the valley is closed. From Dallas the aircraft is already airborne when the forecast changes.
Same airport, same airline, same aircraft: the length of the trip decides whether bad weather turns into a cancellation or a diversion.
The ski country guide covers the rest of the mountain airports, which divert less than Aspen but more than almost anywhere else.
Fog is the second pattern. San Francisco to Arcata, serving a stretch of the northern California coast where fog is routine, diverted 2.24%. Palm Springs to San Francisco diverted 1.77%, the highest of any route with 2,000 or more flights, and almost all of it sits with SkyWest's flights on the route. When San Francisco's low cloud cuts its arrival rate, a short regional flight, which likely carries less spare fuel for holding than a long one, is the first to be sent elsewhere. Seattle to Ketchikan, into the mountains and rain of southeast Alaska, diverted 1.67%.
The third pattern is long flights into crowded eastern airports. Santa Ana to Newark diverted 2.02% and Dallas Love Field to LaGuardia 1.99%. A summer thunderstorm over New York holds arriving flights in the air; a flight that has already crossed the country has less fuel to hold with than one that left Boston an hour earlier.
Distance matters, and Hawaii proves it
Grouping every route on the site by length shows the effect cleanly. Routes under 250 miles diverted around one flight in a thousand; routes over 1,000 miles diverted three times as often or more. More time in the air is more time for a passenger to fall ill, for a system to fail, and for the destination's weather to change after take-off.
Hawaii shows both ends. Honolulu to Kahului, a 100-mile hop, diverted 0.05% of more than ten thousand flights (that route is where I noticed Hawaiian's flights moving to Alaska's code from January 2026, when its record split into two carrier files), and Honolulu has the lowest departure diversion rate of any airport with a page, 0.13%. The inter-island guide covers that network. But San Diego to Honolulu, 2,600 miles over open ocean with no alternate airport on the way, diverted 1.46%, and Alaska's flights on it more than that.
The airports
US average 0.29%
0.00%1.00%
Share of flights departing each airport that landed somewhere other than their destination. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
Airport figures on this site cover departing flights, so this ranking measures where diversions start, not where they were headed. Santa Ana (SNA) leads at 0.46%. The airport sends a large share of its departures on long flights east and to Hawaii from one of the shortest main runways at any big US airport, and the long-haul routes out of Southern California, San Diego included, show up repeatedly near the top of the route list. San Juan and the Florida airports follow, all with long overwater or storm-season flying.
Counted by destination instead, the arrival side, the big airports that receive the most diverted flights are the ones where thunderstorms meet congestion. Among the 60 airports with a page, LaGuardia received the highest share of diverted arrivals, followed by Midway and Dallas-Fort Worth. Short runways at the first two and summer convection at all three likely explain most of it. Oakland and San Jose, across the bay from the fog at San Francisco, sit at the very bottom.
Diversions also track the season. July 2026 diverted about twice the annual rate, the peak month for thunderstorms, and October 2025 the fewest.
The airlines
US average 0.29%
0.00%1.00%
Share of each airline's scheduled flights that landed somewhere other than their destination. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
American Airlines diverted the largest share of its flights, 0.36%, consistent with a network centred on Dallas-Fort Worth and Charlotte in the summer storm belt. Hawaiian Airlines diverted the fewest, 0.13%, with much of its flying on the short inter-island hops. SkyWest ranks high for a reason the route list already gave: it flies the Aspen and mountain routes for all three network carriers, and SkyWest's own Aspen station diverts at about twice the airline's network rate.
What I would do about it
On a mountain route, prefer the connection through the nearby hub. At 4.63% diverted, I would not put anything fixed behind the Dallas nonstop to Aspen. A connection through Denver trades diversion risk for cancellation risk, and a cancellation in Denver leaves you at a hub with options, not at an alternate airport a long drive from where you meant to be.
Carry what you need for a night. A diversion that ends in a cancelled continuation strands passengers at the alternate. Medication, a charger and a change of clothes belong in the cabin bag.
Know your rights. A flight that ends at a different airport is treated like a significant schedule change for refund purposes; the delayed flight rights guide sets out what US rules require and what they do not.
Leave a spare day before anything fixed. On routes that divert several percent of the time, the same-day arrival is not reliable enough for a wedding or a cruise.
Check the routes: Dallas-Fort Worth to Aspen · Denver to Aspen · Palm Springs to San Francisco · San Diego to Honolulu · Methodology