Carrier route record
AAMIA→IAH
American Airlines · Miami to Houston
- Flights
- 1,527
- Period
- July 2025 to June 2026
- Share of route
- 41%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on MIA to IAH sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,527 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,479 at 85.9% on time.
The national on-time rate over the same period is 77.6%, so American on MIA to IAH runs 8 points behind the country as a whole. Across a thousand flights that is about 75 extra late arrivals.
Key figures
On time
70.1%
Arrivals under 15 minutes late, of 1,507 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
1.24%
National rate is 1.81%
Whole route
77.2%
Every carrier on MIA to IAH, 3,737 flights
These figures cover 1,527 flights between July 2025 and June 2026. Beyond the headline rate, 11.1% 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 MIA to IAH
American flew 1,527 of the 3,737 flights on MIA to IAH, about 41% of it. Its 70.1% on time is 7 points worse than the route as a whole, which runs 77.2%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from Envoy at 86.9% to Republic at 64.3%. Three 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 85.9% of the time; Spirit Airlines manages 69.7%. Sample sizes sit next to every figure, because a two-point gap across 440 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 122 | 86.9% | 39 min | 0.00% | A+ |
| United Airlines | 1,479 | 85.9% | 91 min | 0.61% | A+ |
| Frontier Airlinesthin sample | 155 | 78.4% | 97 min | 1.29% | B |
| American Airlines (this page) | 1,527 | 70.1% | 72 min | 1.24% | C |
| Spirit Airlines | 440 | 69.7% | 87 min | 2.73% | C |
| Republic Airwaysthin sample | 14 | 64.3% | 133 min | 0.00% | D+ |
The spread between United and Spirit is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 more arrivals inside the on-time window.
Flight by flight
American flight numbers on MIA to IAH
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 25 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am148 flights87.8%
- 8am–11am210 flights83.8%
- 11am–2pm30 flights—
- 2pm–5pm412 flights63.1%
- 5pm–8pm365 flights64.6%
- 8pm–5am362 flights68.2%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.8% of the time, against 63.1% for the afternoon window. That is 25 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 412 flights scheduled in it.
Across the year
American on MIA to IAH through the year
July is the worst month at 56.2% on time, 27 points below December, the best at 83.5%. 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. March was the busiest month here, with 147 flights.
Across the week, Wednesday is the strongest day at 76.4% on time and Sunday the weakest at 57.8%. 19 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 33,000 reported delay minutes.
- 38%Carrier
- 34%Late-arriving aircraft
- 20%National Airspace System
- 8%Extreme weather
- 0%Security
34% 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 33,000 reported delay minutes here, that single category outweighs weather by 4 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 32,661 reported delay minutes.
The largest share of delay minutes, 38%, 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 12,000 of the 33,000 delay minutes reported here.
Cancellations sit at 1.24% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
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. 11.1% 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 964 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 78.3% on time across 1,526 flights, 8 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 8 points of difference.
The sample behind these figures is 1,527 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 MIA to IAH
Put together: the calendar is the biggest lever here, not the carrier or the hour. December runs 83.5% on time and July 56.2%, a swing of 27 points. If the dates move at all, move them out of July before you think about anything else. 1,507 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to IAH, every carrier
- American on IAH to MIA, the return leg
- Envoy Air on MIA to IAH86.9%
- United Airlines on MIA to IAH85.9%
- Frontier Airlines on MIA to IAH78.4%
- Spirit Airlines on MIA to IAH69.7%
- American Airlines network-wide record
- Miami International (MIA) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
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.