Carrier route record

WNSJU→FLL

Southwest Airlines · San Juan to Fort Lauderdale

Flights: 279
Period: July 2025 to June 2026
Share of route: 12%
Carriers: 4

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

Southwest on SJU to FLL lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 40 minutes on average. That is a workable record, not a spotless one. That rests on 279 flights, with a median arrival 1 minute early.

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

On time

76.3%

Arrivals under 15 minutes late, of 278 completed flights

Avg delay

39 min

Across delayed arrivals only, not all flights

Cancelled

0.36%

National rate is 1.81%

Whole route

75.1%

Every carrier on SJU to FLL, 2,342 flights

These figures cover 279 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Southwest against every carrier on SJU to FLL

Southwest flew 279 of the 2,342 flights on SJU to FLL, about 12% of it. Its 76.3% on time is about level with the route as a whole at 75.1%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Frontier at 81.6% to Spirit at 61.9%. Two 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 FLL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlinesthin sample	128	81.6%	143 min	2.34%	B
JetBlue Airways	1,645	76.6%	71 min	1.28%	B
Southwest Airlines (this page)thin sample	279	76.3%	39 min	0.36%	B+
Spirit Airlinesthin sample	290	61.9%	79 min	2.76%	D

Departure window

When Southwest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 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–8am32 flights96.9%
8am–11am52 flights90.4%
11am–2pm93 flights68.8%
2pm–5pm80 flights71.2%
5pm–8pm22 flights—
8pm–5am—

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 68.8% on time against 96.9% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 93 flights scheduled in it.

Across the year

Southwest on SJU to FLL through the year

Jul–Sep 202575 flights81.3%
Oct–Dec 202591 flights81.3%
Jan–Mar 202671 flights70.0%
Apr–Jun 202642 flights66.7%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 76.3% on time across 279 flights.

Southwest on SJU to FLL did not run the same all year. Its best quarter was Jul–Sep 2025 at 81.3% on time and its weakest Apr–Jun 2026 at 66.7%, a swing of 15 points on roughly 70 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Friday is the strongest day at 83.7% on time and Thursday the weakest at 67.4%. 16 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 62% of the 2,570 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
62%
Carrier
22%
National Airspace System
16%
Security
1%

62% 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 2,570 reported delay minutes here, that single category outweighs weather by 62 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 2,570 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 96.9% on time here.

Cancellations are rare at 0.36%, 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

Badly late arrivals are rare here: only 3.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

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 64.7% on time across 279 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.

One caution: this is a thin sample. 279 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Southwest on SJU to FLL

Put together: treat all of this as provisional. 279 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 76.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 278 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