Carrier route record
AABUF→ORD
American Airlines · Buffalo to Chicago
- Flights
- 476
- Period
- July 2025 to June 2026
- Share of route
- 22%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on BUF to ORD earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 6 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 476 flights. The strongest carrier on the route with a full sample, United Airlines, flew 612 at 74.1% on time.
Set against the rest of the country, American's BUF to ORD record is 6 points better than the US average of 77.6%. That gap is worth roughly 64 fewer late arrivals for every thousand flights.
Key figures
On time
84.0%
Arrivals under 15 minutes late, of 469 completed flights
Avg delay
124 min
Across delayed arrivals only, not all flights
Cancelled
1.47%
National rate is 1.81%
Whole route
74.0%
Every carrier on BUF to ORD, 2,196 flights
These figures cover 476 flights between July 2025 and June 2026. The median arrival is 12 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
American against every carrier on BUF to ORD
American flew 476 of the 2,196 flights on BUF to ORD, about 22% of it. Its 84.0% on time is 10 points better than the route as a whole, which runs 74.0%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from American at 84.0% to SkyWest at 60.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines (this page) | 476 | 84.0% | 124 min | 1.47% | B |
| Republic Airwaysthin sample | 355 | 76.2% | 95 min | 3.66% | B− |
| United Airlines | 612 | 74.1% | 88 min | 1.47% | C |
| Envoy Air | 423 | 70.8% | 68 min | 3.31% | C− |
| SkyWest Airlinesthin sample | 330 | 60.2% | 134 min | 6.06% | D− |
Envoy Air cancels 3.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after 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 20 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am272 flights86.2%
- 8am–11am74 flights81.9%
- 11am–2pm77 flights88.3%
- 2pm–5pm48 flights68.1%
- 5pm–8pm5 flights—
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 88.3% on time, ahead of 2pm–5pm at 68.1%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5am–8am window is the busiest, with 272 flights scheduled in it.
Across the year
American on BUF to ORD through the year
December is the weak month at 68.8% on time, against 91.7% in October. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 81 flights.
Across the week, Wednesday is the strongest day at 89.6% on time and Saturday the weakest at 78.8%. 11 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. Carrier accounts for 63% of the 9,293 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.
- 63%Carrier
- 18%Late-arriving aircraft
- 17%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 63%, 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 5,822 of the 9,293 delay minutes reported here. The split is drawn from 9,293 reported delay minutes.
Cancellations sit at 1.47% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
6.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last close to two hours, which a normal layover absorbs.
At 474 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 58.8% on time across 476 flights, 25 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 25 points of difference.
One caution: this is a thin sample. 476 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking American on BUF to ORD
Put together: treat all of this as provisional. 476 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 469 completed flights over 12 months sit behind that.
Related
Where to go next
- BUF to ORD, every carrier
- American on ORD to BUF, the return leg
- Republic Airways on BUF to ORD76.2%
- United Airlines on BUF to ORD74.1%
- Envoy Air on BUF to ORD70.8%
- SkyWest Airlines on BUF to ORD60.2%
- American Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.