Carrier route record
AABOS→MIA
American Airlines · Boston to Miami
- Flights
- 2,231
- Period
- July 2025 to June 2026
- Share of route
- 65%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on BOS to MIA lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,231 flights, with a median arrival 13 minutes early.
Set against the rest of the country, American's BOS to MIA record is 5 points better than the US average of 77.6%. That gap is worth roughly 47 fewer late arrivals for every thousand flights.
Key figures
On time
82.3%
Arrivals under 15 minutes late, of 2,186 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
1.75%
National rate is 1.81%
Whole route
77.7%
Every carrier on BOS to MIA, 3,417 flights
These figures cover 2,231 flights between July 2025 and June 2026. The median arrival is 13 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 BOS to MIA
American flew 2,231 of the 3,417 flights on BOS to MIA, most of the route. Its 82.3% on time is 5 points better than the route as a whole, which runs 77.7%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from American at 82.3% to Republic at 47.6%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines (this page) | 2,231 | 82.3% | 74 min | 1.75% | B |
| JetBlue Airwaysthin sample | 88 | 72.6% | 71 min | 3.41% | C− |
| Delta Air Lines | 890 | 72.1% | 76 min | 2.70% | C |
| Spirit Airlinesthin sample | 187 | 54.0% | 82 min | 5.88% | F− |
| Republic Airwaysthin sample | 21 | 47.6% | 50 min | 0.00% | F+ |
Flight by flight
American flight numbers on BOS to MIA
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 26 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am794 flights94.6%
- 8am–11am306 flights84.3%
- 11am–2pm505 flights77.9%
- 2pm–5pm261 flights68.3%
- 5pm–8pm362 flights70.7%
- 8pm–5am3 flights—
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.6% of the time, against 68.3% for the afternoon window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 794 flights scheduled in it.
Across the year
American on BOS to MIA through the year
December is the weak month at 76.0% on time, against 89.6% in June. 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 212 flights.
Across the week, Wednesday is the strongest day at 86.9% on time and Sunday the weakest at 75.4%. 12 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 29,000 reported delay minutes.
- 36%Carrier
- 33%Late-arriving aircraft
- 27%National Airspace System
- 4%Extreme weather
The largest share of delay minutes, 36%, 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 10,000 of the 29,000 delay minutes reported here. The split is drawn from 28,514 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 94.6% on time here.
Cancellations sit at 1.75% against a national 1.81%, which is ordinary. Diversions add another 0.27%.
Connections and stage length
What a delay here costs
6.5% 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 a little over an hour, which a normal layover absorbs.
The 1,258 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 70.7% on time across 2,230 flights, 12 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 12 points of difference.
The sample behind these figures is 2,231 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 BOS to MIA
Put together: the calendar is the biggest lever here, not the carrier or the hour. June runs 89.6% on time and December 76.0%, a swing of 14 points. If the dates move at all, move them out of December before you think about anything else. 2,186 completed flights over 12 months sit behind that.
Related
Where to go next
- BOS to MIA, every carrier
- American on MIA to BOS, the return leg
- Delta Air Lines on BOS to MIA72.1%
- Spirit Airlines on BOS to MIA54.0%
- American Airlines network-wide record
- Boston Logan International (BOS) delay statistics
- Miami International (MIA) 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.