Carrier route record
F9RDU→PHL
Frontier Airlines · Raleigh to Philadelphia
- Flights
- 585
- Period
- July 2025 to June 2026
- Share of route
- 23%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on RDU to PHL sits in the middle of the pack with a C−. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 585 flights. The strongest carrier on the route with a full sample, American Airlines, flew 1,105 at 72.5% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Frontier on RDU to PHL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.0%
Arrivals under 15 minutes late, of 557 completed flights
Avg delay
99 min
Across delayed arrivals only, not all flights
Cancelled
4.62%
National rate is 1.81%
Whole route
73.5%
Every carrier on RDU to PHL, 2,562 flights
These figures cover 585 flights between July 2025 and June 2026. Beyond the headline rate, 11.7% 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 RDU to PHL
Frontier flew 585 of the 2,562 flights on RDU to PHL, about 23% of it. Its 74.0% on time is about level with the route as a whole at 73.5%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Republic at 85.0% to PSA at 70.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 2 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 | 216 | 85.0% | 66 min | 3.70% | A− |
| Frontier Airlines (this page) | 585 | 74.0% | 99 min | 4.62% | C− |
| American Airlines | 1,105 | 72.5% | 101 min | 2.35% | C |
| PSA Airlines | 656 | 70.8% | 83 min | 4.42% | C− |
PSA Airlines cancels 4.4% 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.
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 14 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1 flights—
- 8am–11am174 flights81.3%
- 11am–2pm38 flights76.3%
- 2pm–5pm96 flights67.8%
- 5pm–8pm70 flights75.4%
- 8pm–5am206 flights69.1%
Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 81.3% of the time, against 67.8% for the afternoon window. That is 14 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 206 flights scheduled in it.
Across the year
Frontier on RDU to PHL through the year
July is the worst month at 59.5% on time, 22 points below May, the best at 81.8%. 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 59 flights.
Across the week, Friday is the strongest day at 82.7% on time and Sunday the weakest at 62.9%. 20 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 69% of the 14,000 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.
- 69%Late-arriving aircraft
- 18%National Airspace System
- 12%Carrier
- 1%Extreme weather
69% 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 14,000 reported delay minutes here, that single category outweighs weather by 69 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 14,310 reported delay minutes.
The practical consequence: the 8am–11am 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 4.62%, against 1.81% nationally. That is roughly one flight in twenty 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. 11.7% 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.
At 337 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 81.2% on time across 585 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.
One caution: this is a thin sample. 585 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 RDU to PHL
Put together: the delay figures matter less here than the 4.62% cancellation rate. A late arrival costs you an hour and a half; 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. 557 completed flights over 12 months sit behind that.
Related
Where to go next
- RDU to PHL, every carrier
- Frontier on PHL to RDU, the return leg
- Republic Airways on RDU to PHL85.0%
- American Airlines on RDU to PHL72.5%
- PSA Airlines on RDU to PHL70.8%
- Frontier Airlines network-wide record
- Raleigh-Durham International (RDU) 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.