Carrier route record
AAMIA→ATL
American Airlines · Miami to Atlanta
- Flights
- 1,524
- Period
- July 2025 to June 2026
- Share of route
- 24%
- 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 ATL draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 1,524 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 3,300 at 76.7% on time.
The national on-time rate over the same period is 77.6%, so American on MIA to ATL runs 10 points behind the country as a whole. Across a thousand flights that is about 101 extra late arrivals.
Key figures
On time
67.5%
Arrivals under 15 minutes late, of 1,510 completed flights
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
0.79%
National rate is 1.81%
Whole route
73.7%
Every carrier on MIA to ATL, 6,223 flights
These figures cover 1,524 flights between July 2025 and June 2026. Beyond the headline rate, 12.8% 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 ATL
American flew 1,524 of the 6,223 flights on MIA to ATL, about 24% of it. Its 67.5% on time is 6 points worse than the route as a whole, which runs 73.7%. Ranked by on-time rate it is number five of six carriers on the route, where the range runs from Envoy at 78.3% to Republic at 65.9%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 5 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 |
|---|---|---|---|---|---|
| Envoy Airthin sample | 225 | 78.3% | 47 min | 1.33% | B |
| Delta Air Lines | 3,300 | 76.7% | 83 min | 1.39% | B |
| Spirit Airlinesthin sample | 269 | 74.4% | 71 min | 4.09% | C− |
| Frontier Airlines | 861 | 71.8% | 79 min | 1.86% | C |
| American Airlines (this page) | 1,524 | 67.5% | 82 min | 0.79% | C+ |
| Republic Airwaysthin sample | 44 | 65.9% | 60 min | 0.00% | C+ |
No carrier stands out. Delta tops the table at 76.7%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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 34 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am82 flights87.7%
- 8am–11am288 flights85.0%
- 11am–2pm29 flights—
- 2pm–5pm282 flights54.1%
- 5pm–8pm275 flights65.2%
- 8pm–5am568 flights63.0%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.7% of the time, against 54.1% for the afternoon window. That is 34 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 568 flights scheduled in it.
Across the year
American on MIA to ATL through the year
August is the worst month at 50.8% on time, 30 points below December, the best at 80.8%. 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. July was the busiest month here, with 155 flights.
Across the week, Tuesday is the strongest day at 79.6% on time and Sunday the weakest at 54.5%. 25 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 40,000 reported delay minutes.
- 41%Carrier
- 38%Late-arriving aircraft
- 16%National Airspace System
- 5%Extreme weather
- 0%Security
38% 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 40,000 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 40,265 reported delay minutes.
The largest share of delay minutes, 41%, 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 16,000 of the 40,000 delay minutes reported here.
Cancellations are rare at 0.79%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
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. 12.8% 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 594 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 75.2% on time across 1,527 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 1,524 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 ATL
Put together: the calendar is the biggest lever here, not the carrier or the hour. December runs 80.8% on time and August 50.8%, a swing of 30 points. If the dates move at all, move them out of August before you think about anything else. 1,510 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to ATL, every carrier
- American on ATL to MIA, the return leg
- Envoy Air on MIA to ATL78.3%
- Delta Air Lines on MIA to ATL76.7%
- Spirit Airlines on MIA to ATL74.4%
- Frontier Airlines on MIA to ATL71.8%
- American Airlines network-wide record
- Miami International (MIA) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) 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.