Carrier route record
AAORD→SEA
American Airlines · Chicago to Seattle
- Flights
- 1,336
- Period
- July 2025 to June 2026
- Share of route
- 24%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on ORD to SEA draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 1,336 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,535 at 73.6% on time.
United Airlines is the most reliable of the three carriers covered here at 73.6% on time across 1,535 flights.
Key figures
On time
63.5%
Arrivals under 15 minutes late, of 1,308 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
2.02%
National rate is 1.81%
Whole route
68.5%
Every carrier on ORD to SEA, 5,572 flights
These figures cover 1,336 flights between July 2025 and June 2026. Beyond the headline rate, 12.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
American against every carrier on ORD to SEA
American flew 1,336 of the 5,572 flights on ORD to SEA, about 24% of it. Its 63.5% on time is 5 points worse than the route as a whole, which runs 68.5%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from United at 73.6% to American at 63.5%.
The choice of carrier is not cosmetic here. United Airlines arrives on time 73.6% of the time; Alaska Airlines manages 67.5%. Sample sizes sit next to every figure, because a two-point gap across 1,799 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,535 | 73.6% | 59 min | 0.72% | C+ |
| Delta Air Lines | 902 | 68.8% | 66 min | 1.44% | C |
| Alaska Airlines | 1,799 | 67.5% | 63 min | 1.67% | C |
| American Airlines (this page) | 1,336 | 63.5% | 70 min | 2.02% | D |
United leads Alaska by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
When American runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am244 flights79.2%
- 8am–11am249 flights65.0%
- 11am–2pm258 flights70.6%
- 2pm–5pm30 flights80.0%
- 5pm–8pm190 flights54.0%
- 8pm–5am365 flights50.3%
Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 50.3% on time, against 80.0% for the 2pm–5pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 365 flights scheduled in it.
Across the year
American on ORD to SEA through the year
September is the best month on the calendar at 85.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. August was the busiest month here, with 153 flights.
Across the week, Tuesday is the strongest day at 75.3% on time and Friday the weakest at 55.4%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why American runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 33,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 44%Late-arriving aircraft
- 35%Carrier
- 18%National Airspace System
- 3%Extreme weather
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 33,000 reported delay minutes here, that single category outweighs weather by 16 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 33,178 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 12,000 of the 33,000 delay minutes reported here.
Cancellations sit at 2.02% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 12.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 1,721 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 71.2% on time across 1,336 flights, 8 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 8 points of difference.
The sample behind these figures is 1,336 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking American on ORD to SEA
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 85.3% on time and March 38.8%, a swing of 47 points. If the dates move at all, move them out of March before you think about anything else. 1,308 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to SEA, every carrier
- American on SEA to ORD, the return leg
- United Airlines on ORD to SEA73.6%
- Delta Air Lines on ORD to SEA68.8%
- Alaska Airlines on ORD to SEA67.5%
- American Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.