Carrier route record
AASEA→ORD
American Airlines · Seattle to Chicago
- 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 SEA to ORD sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 1,336 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,534 at 79.8% on time.
United Airlines is the most reliable of the three carriers covered here at 79.8% on time across 1,534 flights.
Key figures
On time
71.2%
Arrivals under 15 minutes late, of 1,295 completed flights
Avg delay
93 min
Across delayed arrivals only, not all flights
Cancelled
2.02%
National rate is 1.81%
Whole route
75.0%
Every carrier on SEA to ORD, 5,566 flights
These figures cover 1,336 flights between July 2025 and June 2026. Beyond the headline rate, 11.1% 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 SEA to ORD
American flew 1,336 of the 5,566 flights on SEA to ORD, about 24% of it. Its 71.2% on time is 4 points worse than the route as a whole, which runs 75.0%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from United at 79.8% to American at 71.2%.
The choice of carrier is not cosmetic here. United Airlines arrives on time 79.8% of the time; Alaska Airlines manages 72.3%. Sample sizes sit next to every figure, because a two-point gap across 1,794 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,534 | 79.8% | 81 min | 0.91% | B+ |
| Delta Air Lines | 902 | 77.5% | 71 min | 1.22% | B |
| Alaska Airlines | 1,794 | 72.3% | 55 min | 1.06% | C |
| American Airlines (this page) | 1,336 | 71.2% | 93 min | 2.02% | C |
United leads Alaska by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
American flight numbers on SEA to ORD
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 32 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am262 flights88.4%
- 8am–11am205 flights70.4%
- 11am–2pm307 flights66.9%
- 2pm–5pm302 flights56.7%
- 5pm–8pm—
- 8pm–5am260 flights76.2%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.4% of the time, against 56.7% for the afternoon window. That is 32 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 307 flights scheduled in it.
Across the year
American on SEA to ORD through the year
August is the worst month at 52.1% on time, 35 points below February, the best at 86.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. August was the busiest month here, with 152 flights.
Across the week, Tuesday is the strongest day at 82.4% on time and Sunday the weakest at 65.2%. 17 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 45% of the 35,000 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.
- 45%Late-arriving aircraft
- 34%Carrier
- 17%National Airspace System
- 4%Extreme weather
45% 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 35,000 reported delay minutes here, that single category outweighs weather by 11 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 34,589 reported delay minutes.
The largest share of delay minutes, 34%, 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 35,000 delay minutes reported here.
Cancellations sit at 2.02% against a national 1.81%, which is ordinary. Diversions add another 1.05%.
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. 11.1% 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 63.5% on time across 1,336 flights, 8 points below 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 SEA to ORD
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 86.8% on time and August 52.1%, a swing of 35 points. If the dates move at all, move them out of August before you think about anything else. 1,295 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to ORD, every carrier
- American on ORD to SEA, the return leg
- United Airlines on SEA to ORD79.8%
- Delta Air Lines on SEA to ORD77.5%
- Alaska Airlines on SEA to ORD72.3%
- American Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Chicago O'Hare International (ORD) 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.