Carrier route record
AAORD→SFO
American Airlines · Chicago to San Francisco
- Flights
- 1,764
- 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 ORD to SFO 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 1,764 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.6%, so American on ORD to SFO runs 14 points behind the country as a whole. Across a thousand flights that is about 144 extra late arrivals.
Key figures
On time
63.2%
Arrivals under 15 minutes late, of 1,730 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.76%
National rate is 1.81%
Whole route
67.6%
Every carrier on ORD to SFO, 5,627 flights
These figures cover 1,764 flights between July 2025 and June 2026. Beyond the headline rate, 14.0% 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 SFO
American flew 1,764 of the 5,627 flights on ORD to SFO, about 31% of it. Its 63.2% on time is 4 points worse than the route as a whole, which runs 67.6%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 69.8% to Alaska at 57.4%. 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 | 3,813 | 69.8% | 73 min | 1.05% | C |
| American Airlines (this page) | 1,764 | 63.2% | 73 min | 1.76% | D |
| Alaska Airlinesthin sample | 50 | 57.4% | 59 min | 6.00% | D− |
Flight by flight
American flight numbers on ORD to SFO
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 44 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–8am262 flights87.2%
- 8am–11am518 flights62.9%
- 11am–2pm197 flights62.9%
- 2pm–5pm185 flights69.7%
- 5pm–8pm439 flights53.6%
- 8pm–5am163 flights42.9%
Scale runs 35% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 42.9% on time, against 87.2% for the 5am–8am 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 8am–11am window is the busiest, with 518 flights scheduled in it.
Across the year
American on ORD to SFO through the year
June is the worst month at 43.7% on time, 33 points below September, the best at 76.4%. 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. May was the busiest month here, with 189 flights.
Across the week, Tuesday is the strongest day at 70.9% on time and Sunday the weakest at 55.9%. 15 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 47% of the 47,000 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.
- 47%Late-arriving aircraft
- 25%Carrier
- 24%National Airspace System
- 3%Extreme weather
- 0%Security
47% 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 47,000 reported delay minutes here, that single category outweighs weather by 18 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 46,779 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.2% on time here.
Cancellations sit at 1.76% against a national 1.81%, which is ordinary. Diversions add another 0.17%.
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. 14.0% 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 73.2% on time across 1,763 flights, 10 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 10 points of difference.
The sample behind these figures is 1,764 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 SFO
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 76.4% on time and June 43.7%, a swing of 33 points. If the dates move at all, move them out of June before you think about anything else. 1,730 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to SFO, every carrier
- American on SFO to ORD, the return leg
- United Airlines on ORD to SFO69.8%
- American Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- San Francisco International (SFO) 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.