Route reliability record
PHL→SJU
Philadelphia to San Juan
- Flights
- 1,992
- Period
- September 2025 to August 2026
- Distance
- 1,576 mi
- Carriers
- 4
This route carries a cancellation problem, not just a delay problem: 3.4% of scheduled flights never operate, against 1.9% nationally. Of the ones that do fly, about two flights in three arrive on time, worth a D− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,992 PHL to SJU flights, of which American Airlines flew 763 at 71.4% on time.
Best time to fly PHL to SJU: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 75.5% of the time and Tuesday flights 70.0%, against 63.3% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 14 points behind the country as a whole. Across a thousand flights that is about 140 extra late arrivals.
Key figures
On time
63.3%
Arrivals under 15 minutes late, of 1,918 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
3.36%
National rate is 1.89%
Best carrier
American
71.4% on time across 763 flights
These figures cover 1,992 flights between September 2025 and August 2026. Beyond the headline rate, 14.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on PHL to SJU
The choice of carrier is not cosmetic here. American Airlines arrives on time 71.4% of the time; Frontier Airlines manages 55.6%. Sample sizes sit next to every figure, because a two-point gap across 915 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 763 | 71.4% | 77 min | 1.97% | C |
| JetBlue Airwaysthin sample | 159 | 70.2% | 94 min | 4.40% | C− |
| Spirit Airlinesthin sample | 155 | 61.9% | 67 min | 10.32% | D− |
| Frontier Airlines | 915 | 55.6% | 77 min | 3.17% | D− |
Frontier Airlines cancels 3.2% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Flight by flight
Flights on PHL to SJU
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Philadelphia to San Juan
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PHL → SJUPhiladelphia to San Juan | American Airlines | 70.0% | 71.4% | 1.97% | 8am–11am, Tue | — |
| 2. PHL → SJUPhiladelphia to San Juan | Frontier Airlines | 53.8% | 55.6% | 3.17% | 5am–8am, Wed | F9 1016 06:00 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 29 points, against 16 points between the best and worst carrier.
- 5am–8am173 flights66.7%
- 8am–11am383 flights75.5%
- 11am–2pm477 flights66.2%
- 2pm–5pm104 flights46.5%
- 5pm–8pm349 flights60.5%
- 8pm–5am506 flights55.3%
Scale runs 40% to 80%.
Book the morning departure. Flights leaving between 8am–11am arrive on time 75.5% of the time, against 46.5% for the afternoon window. That is 29 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 506 flights scheduled in it.
Explore
Filter PHL to SJU by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On PHL to SJU, the best departure window is 8am–11am at 75.5% on time and the worst is 2pm–5pm at 46.5%, a wide gap of 29.0 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am66.7%
- 8–11am75.5%
- 11am–2pm66.2%
- 2–5pm46.5%
- 5–8pm60.5%
- 8pm–5am55.3%
best all US flightsScale 40% to 95%.
Across the year
When delays peak on this route
This route's year swings by 28 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.
July is the worst month at 50.0% on time, 28 points below May, the best at 77.6%. 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. April was the busiest month here, with 224 flights.
Across the week, Tuesday is the strongest day at 70.0% on time and Monday the weakest at 58.8%, a spread of 11 points.
Delay causes
Why this route gets delayed
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 54,000 reported delay minutes.
- 36%Carrier
- 34%Late-arriving aircraft
- 22%National Airspace System
- 7%Extreme weather
- 0%Security
34% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 54,000 reported delay minutes here, that single category outweighs weather by 5 to one. The split is drawn from 54,448 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 19,000 of the 54,000 delay minutes reported here.
Cancellations run at 3.36%, against 1.89% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
14.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,576 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 71.9% on time across 1,992 flights, 9 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 9 points of difference.
The sample behind these figures is 1,992 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.
Work out the risk of missing a connection in SJU after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.36% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 1,918 completed flights over 12 months sit behind that.
Common questions
PHL to SJU questions
How often is PHL to SJU delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 36.7% of the 1,992 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on PHL to SJU?
American Airlines leads at 71.4% on time across 763 flights. Frontier Airlines is at the other end on 55.6%, a gap of 16 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on PHL to SJU?
The 8am–11am departure window is the strongest at 75.5% on time. The 2pm–5pm window is the weakest at 46.5%, 29 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 July delays on PHL to SJU?
July is the weakest month at 50.0% on time, compared with 77.6% in May. Across the year that is 28 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 PHL — the return legseparate record
- Philadelphia International (PHL) delay statistics
- Luis Munoz Marin International (SJU) delay statistics
- American Airlines on PHL to SJU71.4%
- JetBlue Airways on PHL to SJU70.2%
- Spirit Airlines on PHL to SJU61.9%
- Frontier Airlines on PHL to SJU55.6%
- PHL to ATL, a related route78.0%
- MCO to SJU, a related route73.8%
- PHL to MCO, a related route72.4%
- American Airlines on-time record71.4%
- JetBlue Airways on-time record70.2%
- Spirit Airlines on-time record61.9%
- The US routes with the most cancellations
- Same route, different airline: where the carrier you pick matters most
Direction matters. PHL to SJU and SJU to PHL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.