Carrier route record
F9ATL→PHL
Frontier Airlines · Atlanta to Philadelphia
- Flights
- 1,010
- Period
- July 2025 to June 2026
- Share of route
- 18%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on ATL to PHL draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 1,010 flights. The strongest carrier on the route with a full sample, PSA Airlines, flew 834 at 81.5% on time.
PSA Airlines is the most reliable of the three carriers covered here at 81.5% on time across 834 flights.
Key figures
On time
62.4%
Arrivals under 15 minutes late, of 978 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
2.97%
National rate is 1.81%
Whole route
74.9%
Every carrier on ATL to PHL, 5,713 flights
These figures cover 1,010 flights between July 2025 and June 2026. Beyond the headline rate, 17.6% 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
Frontier against every carrier on ATL to PHL
Frontier flew 1,010 of the 5,713 flights on ATL to PHL, about 18% of it. Its 62.4% on time is 13 points worse than the route as a whole, which runs 74.9%. Ranked by on-time rate it is last of six carriers on the route, where the range runs from Republic at 90.7% to Frontier at 62.4%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The three carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 156 | 90.7% | 95 min | 3.85% | A− |
| PSA Airlines | 834 | 81.5% | 98 min | 4.56% | B− |
| American Airlines | 592 | 78.1% | 120 min | 2.03% | B |
| Delta Air Lines | 3,028 | 76.1% | 52 min | 2.48% | B |
| Spirit Airlinesthin sample | 93 | 65.2% | 72 min | 1.08% | C |
| Frontier Airlines (this page) | 1,010 | 62.4% | 84 min | 2.97% | D |
PSA Airlines cancels 4.6% 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
Frontier flight numbers on ATL to PHL
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 34 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am108 flights81.3%
- 8am–11am312 flights72.8%
- 11am–2pm44 flights75.0%
- 2pm–5pm183 flights58.5%
- 5pm–8pm67 flights50.0%
- 8pm–5am296 flights47.5%
Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 47.5% on time, against 81.3% 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 8am–11am window is the busiest, with 312 flights scheduled in it.
Across the year
Frontier on ATL to PHL through the year
July is the worst month at 37.0% on time, 41 points below October, 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. June was the busiest month here, with 112 flights.
Across the week, Tuesday is the strongest day at 72.1% on time and Monday the weakest at 51.3%. 21 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 58% of the 31,000 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.
- 58%Late-arriving aircraft
- 29%Carrier
- 12%National Airspace System
- 1%Extreme weather
58% 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 31,000 reported delay minutes here, that single category outweighs weather by 42 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 30,993 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 81.3% on time here.
Cancellations run at 2.97%, against 1.81% nationally. That is roughly 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 17.6% 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 666 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 66.4% on time across 1,008 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 1,010 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 ATL to PHL
Put together: the delay figures matter less here than the 2.97% cancellation rate. A late arrival costs you an hour and a half; 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. 978 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to PHL, every carrier
- Frontier on PHL to ATL, the return leg
- Republic Airways on ATL to PHL90.7%
- PSA Airlines on ATL to PHL81.5%
- American Airlines on ATL to PHL78.1%
- Delta Air Lines on ATL to PHL76.1%
- Frontier Airlines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.