Carrier route record
AAORD→LAS
American Airlines · Chicago to Las Vegas
- Flights
- 1,852
- Period
- July 2025 to June 2026
- Share of route
- 35%
- 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 LAS 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 1,852 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,328 at 79.6% on time.
The national on-time rate over the same period is 77.6%, so American on ORD to LAS runs 11 points behind the country as a whole. Across a thousand flights that is about 108 extra late arrivals.
Key figures
On time
66.8%
Arrivals under 15 minutes late, of 1,799 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
2.21%
National rate is 1.81%
Whole route
73.7%
Every carrier on ORD to LAS, 5,297 flights
These figures cover 1,852 flights between July 2025 and June 2026. Beyond the headline rate, 12.4% 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 LAS
American flew 1,852 of the 5,297 flights on ORD to LAS, about 35% of it. Its 66.8% on time is 7 points worse than the route as a whole, which runs 73.7%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Spirit at 83.7% to Frontier at 58.3%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 79.6% of the time; Southwest Airlines manages 72.1%. Sample sizes sit next to every figure, because a two-point gap across 670 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 261 | 83.7% | 73 min | 1.15% | B |
| United Airlines | 2,328 | 79.6% | 64 min | 0.43% | B+ |
| Southwest Airlines | 670 | 72.1% | 69 min | 0.75% | C+ |
| American Airlines (this page) | 1,852 | 66.8% | 71 min | 2.21% | C |
| Frontier Airlinesthin sample | 186 | 58.3% | 124 min | 5.91% | D− |
United leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh 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 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–8am303 flights85.9%
- 8am–11am315 flights73.1%
- 11am–2pm180 flights71.3%
- 2pm–5pm240 flights60.9%
- 5pm–8pm376 flights62.2%
- 8pm–5am438 flights53.9%
Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 53.9% on time, against 85.9% 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 8pm–5am window is the busiest, with 438 flights scheduled in it.
Across the year
American on ORD to LAS through the year
November is the best month on the calendar at 86.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. April was the busiest month here, with 196 flights.
Across the week, Tuesday is the strongest day at 77.0% on time and Sunday the weakest at 55.1%. 22 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 49% of the 43,000 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.
- 49%Late-arriving aircraft
- 31%Carrier
- 15%National Airspace System
- 6%Extreme weather
- 0%Security
49% 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 43,000 reported delay minutes here, that single category outweighs weather by 8 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 42,629 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 85.9% on time here.
Cancellations sit at 2.21% against a national 1.81%, which is ordinary. Diversions add another 0.65%.
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. 12.4% 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 1,514 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 76.2% on time across 1,848 flights, 9 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 9 points of difference.
The sample behind these figures is 1,852 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 LAS
Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 86.7% on time and April 55.5%, a swing of 31 points. If the dates move at all, move them out of April before you think about anything else. 1,799 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to LAS, every carrier
- American on LAS to ORD, the return leg
- Spirit Airlines on ORD to LAS83.7%
- United Airlines on ORD to LAS79.6%
- Southwest Airlines on ORD to LAS72.1%
- Frontier Airlines on ORD to LAS58.3%
- American Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Harry Reid International (LAS) 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.