Carrier route record
AASFO→ORD
American Airlines · San Francisco to Chicago
- Flights
- 1,763
- Period
- July 2025 to June 2026
- Share of route
- 31%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on SFO to ORD sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 1,763 flights, with a median arrival 8 minutes early.
The national on-time rate over the same period is 77.6%, so American on SFO to ORD runs 4 points behind the country as a whole. Across a thousand flights that is about 44 extra late arrivals.
Key figures
On time
73.2%
Arrivals under 15 minutes late, of 1,720 completed flights
Avg delay
111 min
Across delayed arrivals only, not all flights
Cancelled
1.76%
National rate is 1.81%
Whole route
76.5%
Every carrier on SFO to ORD, 5,628 flights
These figures cover 1,763 flights between July 2025 and June 2026. Beyond the headline rate, 11.2% 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 SFO to ORD
American flew 1,763 of the 5,628 flights on SFO to ORD, about 31% of it. Its 73.2% on time is 3 points worse than the route as a whole, which runs 76.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 78.3% to Alaska at 52.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,815 | 78.3% | 71 min | 1.02% | B |
| American Airlines (this page) | 1,763 | 73.2% | 111 min | 1.76% | C |
| Alaska Airlinesthin sample | 50 | 52.2% | 49 min | 6.00% | F− |
Flight by flight
American flight numbers on SFO 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 37 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am378 flights91.4%
- 8am–11am427 flights78.9%
- 11am–2pm298 flights54.7%
- 2pm–5pm286 flights62.4%
- 5pm–8pm54 flights66.0%
- 8pm–5am320 flights71.9%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 54.7% on time against 91.4% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 427 flights scheduled in it.
Across the year
American on SFO to ORD through the year
Delays peak in April, when the on-time rate falls to 59.1%. December is the strongest month at 88.0%. Moving a flexible trip across that boundary buys 29 points. May was the busiest month here, with 189 flights.
Across the week, Tuesday is the strongest day at 79.1% on time and Sunday the weakest at 69.5%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why American runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 51,000 reported delay minutes.
- 42%Carrier
- 41%Late-arriving aircraft
- 13%National Airspace System
- 5%Extreme weather
- 0%Security
41% 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 51,000 reported delay minutes here, that single category outweighs weather by 9 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 51,294 reported delay minutes.
The largest share of delay minutes, 42%, 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 21,000 of the 51,000 delay minutes reported here.
Cancellations sit at 1.76% against a national 1.81%, which is ordinary. Diversions add another 0.68%.
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. 11.2% 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 1,846 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 63.2% on time across 1,764 flights, 10 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 10 points of difference.
The sample behind these figures is 1,763 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 SFO to ORD
Put together: the calendar is the biggest lever here, not the carrier or the hour. December runs 88.0% on time and April 59.1%, a swing of 29 points. If the dates move at all, move them out of April before you think about anything else. 1,720 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to ORD, every carrier
- American on ORD to SFO, the return leg
- United Airlines on SFO to ORD78.3%
- American Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.