Carrier route record
AAORD→DEN
American Airlines · Chicago to Denver
- Flights
- 1,471
- Period
- July 2025 to June 2026
- Share of route
- 24%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on ORD to DEN draws a C. About 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 1,471 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,758 at 77.4% on time.
The national on-time rate over the same period is 77.6%, so American on ORD to DEN runs 11 points behind the country as a whole. Across a thousand flights that is about 111 extra late arrivals.
Key figures
On time
66.5%
Arrivals under 15 minutes late, of 1,440 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
1.77%
National rate is 1.81%
Whole route
74.2%
Every carrier on ORD to DEN, 6,169 flights
These figures cover 1,471 flights between July 2025 and June 2026. Beyond the headline rate, 14.1% 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 ORD to DEN
American flew 1,471 of the 6,169 flights on ORD to DEN, about 24% of it. Its 66.5% on time is 8 points worse than the route as a whole, which runs 74.2%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 77.4% to American at 66.5%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 4 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 |
|---|---|---|---|---|---|
| United Airlines | 3,758 | 77.4% | 73 min | 0.93% | B+ |
| Envoy Airthin sample | 125 | 76.0% | 52 min | 0.00% | B+ |
| Southwest Airlines | 483 | 73.0% | 68 min | 1.66% | C |
| Frontier Airlinesthin sample | 332 | 72.5% | 139 min | 2.11% | C |
| American Airlines (this page) | 1,471 | 66.5% | 76 min | 1.77% | C |
No carrier stands out. United tops the table at 77.4%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
American flight numbers on ORD to DEN
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 31 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am172 flights83.4%
- 8am–11am373 flights72.6%
- 11am–2pm199 flights67.0%
- 2pm–5pm339 flights63.3%
- 5pm–8pm90 flights52.8%
- 8pm–5am298 flights56.1%
Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 52.8% on time, against 83.4% 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 373 flights scheduled in it.
Across the year
American on ORD to DEN through the year
December is the weak month at 53.6% on time, against 76.8% 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 155 flights.
Across the week, Tuesday is the strongest day at 73.6% on time and Monday the weakest at 59.7%. 14 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 50% of the 37,000 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.
- 50%Late-arriving aircraft
- 29%Carrier
- 17%National Airspace System
- 3%Extreme weather
- 1%Security
50% 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 37,000 reported delay minutes here, that single category outweighs weather by 17 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 36,634 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 83.4% on time here.
Cancellations sit at 1.77% against a national 1.81%, which is ordinary. Diversions add another 0.34%.
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. 14.1% 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.
The 888 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 73.0% on time across 1,469 flights, 7 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 7 points of difference.
The sample behind these figures is 1,471 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 DEN
Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 76.8% on time and December 53.6%, a swing of 23 points. If the dates move at all, move them out of December before you think about anything else. 1,440 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to DEN, every carrier
- American on DEN to ORD, the return leg
- United Airlines on ORD to DEN77.4%
- Envoy Air on ORD to DEN76.0%
- Southwest Airlines on ORD to DEN73.0%
- Frontier Airlines on ORD to DEN72.5%
- American Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Denver International (DEN) 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.