Carrier route record
F9SJU→PHL
Frontier Airlines · San Juan to Philadelphia
- Flights
- 916
- Period
- September 2025 to August 2026
- Share of route
- 46%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on SJU to PHL draws a D−. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 916 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so Frontier on SJU to PHL 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 884 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
3.17%
National rate is 1.89%
Whole route
71.9%
Every carrier on SJU to PHL, 1,992 flights
These figures cover 916 flights between September 2025 and August 2026. Beyond the headline rate, 12.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Frontier against every carrier on SJU to PHL
Frontier flew 916 of the 1,992 flights on SJU to PHL, about 46% of it. Its 63.3% on time is 9 points worse than the route as a whole, which runs 71.9%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from JetBlue at 90.7% to Spirit at 60.9%. 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airwaysthin sample | 159 | 90.7% | 65 min | 4.40% | A− |
| American Airlines | 763 | 80.3% | 100 min | 2.62% | B |
| Frontier Airlines (this page) | 916 | 63.3% | 81 min | 3.17% | D− |
| Spirit Airlinesthin sample | 154 | 60.9% | 71 min | 10.39% | D− |
Flight by flight
Frontier flight numbers on SJU to PHL
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against half a point between the best and worst carrier.
- 5am–8am151 flights78.9%
- 8am–11am19 flights—
- 11am–2pm188 flights59.7%
- 2pm–5pm155 flights55.8%
- 5pm–8pm130 flights74.0%
- 8pm–5am273 flights56.3%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 78.9% of the time, against 55.8% for the afternoon window. That is 23 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 273 flights scheduled in it.
Across the year
Frontier on SJU to PHL through the year
January is the weak month at 41.3% on time, against 83.1% in May. 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. August was the busiest month here, with 94 flights.
Across the week, Wednesday is the strongest day at 70.5% on time and Monday the weakest at 58.8%, a spread of 12 points.
Arrival by arrival
How late Frontier on SJU to PHL runs when it is late
Frontier on SJU to PHL often beats the schedule: 221 of 884 completed flights, 25%, arrived 15 minutes or more early. The 324 late arrivals split 116 under half an hour, 99 between 30 and 60 minutes, and 109 an hour or more.
- 15+ min early221 flights25.0%
- Within 15 min339 flights38.3%
- 15–29 min late116 flights13.1%
- 30–59 min late99 flights11.2%
- 1–2 hours late65 flights7.4%
- 2+ hours late44 flights5.0%
Scale runs 0% to 100%.
Share of 884 completed flights by arrival against schedule.
52 of 292 late departures made up the time and arrived on time, 18% of them. In the other direction, 84 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at PHL.
The worst days
Worst days for Frontier on SJU to PHL
The latest arrival of the period was on 26 January 2026, 14 hours 22 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 January 2026 | 14 hours 22 minutes | Carrier |
| 4 January 2026 | 13 hours 25 minutes | Carrier |
| 5 April 2026 | 12 hours 37 minutes | Carrier |
| 5 July 2026 | 11 hours 32 minutes | Late-arriving aircraft |
| 31 July 2026 | 10 hours 49 minutes | Late-arriving aircraft |
Delay causes
Why Frontier runs late on this route
Late-arriving aircraft accounts for 53% of the 26,000 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Late-arriving aircraft
- 34%Carrier
- 13%National Airspace System
- 0%Extreme weather
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 26,000 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 26,274 reported delay minutes.
The largest share of delay minutes, 34%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 8,994 of the 26,000 delay minutes reported here.
Cancellations run at 3.17%, 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 costs
12.3% 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 55.6% on time across 915 flights, 8 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 8 points of difference.
One caution: this is a thin sample. 916 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 Frontier on SJU to PHL
Put together: the delay figures matter less here than the 3.17% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 884 completed flights over 12 months sit behind that.
Related
Where to go next
- SJU to PHL, every carrier
- Frontier on PHL to SJU, the return leg
- JetBlue Airways on SJU to PHL90.7%
- American Airlines on SJU to PHL80.3%
- Spirit Airlines on SJU to PHL60.9%
- Frontier Airlines network-wide record
- Luis Munoz Marin International (SJU) delay statistics
- Philadelphia International (PHL) delay statistics
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
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.