Carrier route record

AASJU→MIA

American Airlines · San Juan to Miami

Flights: 2,079
Period: July 2025 to June 2026
Share of route: 79%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.

American on SJU to MIA lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 2,079 flights, with a median arrival 8 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate American on SJU to MIA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

78.5%

Arrivals under 15 minutes late, of 2,063 completed flights

Avg delay

93 min

Across delayed arrivals only, not all flights

Cancelled

0.63%

National rate is 1.81%

Whole route

77.7%

Every carrier on SJU to MIA, 2,642 flights

These figures cover 2,079 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% 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 SJU to MIA

American flew 2,079 of the 2,642 flights on SJU to MIA, most of the route. Its 78.5% on time is about level with the route as a whole at 77.7%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from American at 78.5% to Spirit at 71.1%. One 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.

On-time performance by carrier on SJU to MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines (this page)	2,079	78.5%	93 min	0.63%	B+
Frontier Airlines	379	76.5%	95 min	2.11%	B
Spirit Airlinesthin sample	184	71.1%	94 min	2.17%	C

Flight by flight

American flight numbers on SJU to MIA

AA 161313:3779.3% · 267 flights

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 29 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–8am380 flights93.4%
8am–11am181 flights89.4%
11am–2pm636 flights83.4%
2pm–5pm386 flights68.4%
5pm–8pm479 flights64.5%
8pm–5am17 flights—

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 64.5% on time, against 93.4% 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 11am–2pm window is the busiest, with 636 flights scheduled in it.

Across the year

American on SJU to MIA through the year

Darker means more delays. Figures are on-time percentages.June best, January worst

January is the weak month at 71.3% on time, against 86.1% 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. March was the busiest month here, with 212 flights.

Across the week, Wednesday is the strongest day at 83.8% on time and Sunday the weakest at 71.1%. 13 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 56% of the 41,000 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.

Late-arriving aircraft
56%
Carrier
34%
National Airspace System
7%
Extreme weather
3%
Security
0%

56% 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 41,000 reported delay minutes here, that single category outweighs weather by 20 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 41,364 reported delay minutes.

The largest share of delay minutes, 34%, 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 14,000 of the 41,000 delay minutes reported here.

Cancellations are rare at 0.63%, 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

8.9% 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 an hour and a half, which a normal layover absorbs.

The 1,045 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 runs 76.8% on time across 2,078 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 2,079 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 SJU to MIA

Put together: the calendar is the biggest lever here, not the carrier or the hour. June runs 86.1% on time and January 71.3%, a swing of 15 points. If the dates move at all, move them out of January before you think about anything else. 2,063 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures