Route reliability record
FLL→SJU
Fort Lauderdale to San Juan
- Flights
- 2,344
- Period
- July 2025 to June 2026
- Distance
- 1,046 mi
- Carriers
- 4
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 10 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,344 flights, with a median arrival 0 minutes late.
The national on-time rate over the same period is 77.6%, so this route runs 10 points behind the country as a whole. Across a thousand flights that is about 96 extra late arrivals.
Key figures
On time
68.0%
Arrivals under 15 minutes late, of 2,311 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
1.32%
National rate is 1.81%
Best carrier
JetBlue
71.0% on time across 1,646 flights
These figures cover 2,344 flights between July 2025 and June 2026. Beyond the headline rate, 10.0% 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
Which airline is most reliable on FLL to SJU
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 |
|---|---|---|---|---|---|
| JetBlue Airways | 1,646 | 71.0% | 58 min | 1.22% | C |
| Southwest Airlinesthin sample | 279 | 64.7% | 48 min | 0.36% | D+ |
| Frontier Airlinesthin sample | 128 | 64.2% | 110 min | 3.91% | D− |
| Spirit Airlinesthin sample | 291 | 55.4% | 68 min | 1.72% | D |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 40 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–8am359 flights93.2%
- 8am–11am261 flights75.7%
- 11am–2pm658 flights60.6%
- 2pm–5pm363 flights65.5%
- 5pm–8pm458 flights64.4%
- 8pm–5am245 flights53.1%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 53.1% on time, against 93.2% 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 658 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 31 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
October is the best month on the calendar at 81.6% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 261 flights.
Across the week, Wednesday is the strongest day at 79.7% on time and Sunday the weakest at 58.6%. 21 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 46,000 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.
- 45%Late-arriving aircraft
- 37%Carrier
- 15%National Airspace System
- 3%Extreme weather
- 0%Security
45% 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 46,000 reported delay minutes here, that single category outweighs weather by 15 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 45,544 reported delay minutes.
The largest share of delay minutes, 37%, 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 17,000 of the 46,000 delay minutes reported here.
Cancellations sit at 1.32% against a national 1.81%, which is ordinary. Diversions add another 0.09%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.0% 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 1,046 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 75.1% on time across 2,342 flights, 7 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 7 points of difference.
The sample behind these figures is 2,344 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 81.6% on time and March 50.6%, a swing of 31 points. If the dates move at all, move them out of March before you think about anything else. 2,311 completed flights over 12 months sit behind that.
Common questions
FLL to SJU questions
How often is FLL to SJU delayed?
About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 32.0% of the 2,344 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is FLL to SJU compared with the rest of the country?
68.0% of flights arrive on time here against a national 77.6%, a difference of 10 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on FLL to SJU?
The 5am–8am departure window is the strongest at 93.2% on time. The 8pm–5am window is the weakest at 53.1%, 40 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are March delays on FLL to SJU?
March is the weakest month at 50.6% on time, compared with 81.6% in October. Across the year that is 31 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SJU to FLL — the return legseparate record
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Luis Munoz Marin International (SJU) delay statistics
- JetBlue Airways on-time record71.0%
- Southwest Airlines on-time record64.7%
- Frontier Airlines on-time record64.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. FLL to SJU and SJU to FLL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.