STL to PHL flight delays & on-time performance
Nonstop flights from St. Louis Lambert International Airport to Philadelphia International Airport · 814 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at STL or PHL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from St. Louis (STL) to Philadelphia (PHL) arrived on time 80% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 1.4% were cancelled, and 8% arrived an hour or more late.
- Republic Airways was the most punctual airline here (85% on time); Southwest Airlines was the least (75%).
- Departures scheduled around 8am did best (97% on time); around 8pm did worst (60%).
- Wednesday was the most reliable day to fly (84% on time) and Sunday the least (74%).
- The largest source of delay minutes was late-arriving aircraft (51%).
Which airline is most on time from STL to PHL?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Republic AirwaysRegional airline operating flights for American Eagle, Delta Connection and United Express. | 85% | 1.0% | 17 min | 9.5% | 96 |
| PSA AirlinesRegional airline operating American Eagle flights. | 85% | 6.6% | 13 min | 7.8% | 137 |
| American Airlines | 84% | 1.6% | 22 min | 8.2% | 644 |
| Southwest Airlines | 75% | 0.4% | 16 min | 7.5% | 725 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 5am88%17 flights
- 6am90%338 flights
- 7am86%59 flights
- 8am97%116 flights
- 9am87%40 flights
- 10am85%156 flights
- 11am89%82 flights
- 12pm83%53 flights
- 1pm78%192 flights
- 2pm73%87 flights
- 3pm45%22 flights
- 4pm66%75 flights
- 5pm71%103 flights
- 6pm69%86 flights
- 7pm64%96 flights
- 8pm60%66 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday78%2.9% cancelled
- Tuesday81%0.9% cancelled
- Wednesday84%0.9% cancelled
- Thursday83%0.8% cancelled
- Friday80%0.4% cancelled
- Saturday79%0.6% cancelled
- Sunday74%3.3% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft51%
- Airline (crew, maintenance, cleaning, fueling)36%
- Air traffic control & airport congestion9%
- Extreme weather4%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather83%
- Airline (crew, maintenance, cleaning, fueling)13%
- Air traffic control & airport congestion4%
- Security0%
STL to PHL: common questions
- How often are STL to PHL flights on time?
- 80% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from St. Louis to Philadelphia cancelled?
- 1.4% of scheduled flights were cancelled (23 of 1,602).
- How long are typical delays?
- Across all flights the average arrival delay was 18 min (early arrivals count as zero). Flights that were late arrived 87 min behind schedule on average, and 7.9% of flights were an hour or more late.
- How long is taxi time at STL?
- Flights on this route spent 12 min taxiing from the gate to takeoff on average.
Related routes
Return trip: PHL to STL — 78% on time
More flights from St. Louis
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: STL → PHL, nonstop flights by US airlines that report to the DOT. How we calculate this.