Best Time to Fly PHL to STL: On-Time Stats by Hour & Airline
Philadelphia International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 77.8% of Philadelphia (PHL) to St. Louis (STL) flights arrived on time (1,606 scheduled flights). That is in line with the national average of 77.6%.
Republic Airways was the most punctual of the 4 airlines on the route at 85.3%, while PSA Airlines trailed at 76.0%.
October has been the best month (85% on time) and Thursday the weakest day of the week (74%).
1.6% of flights were cancelled, versus 1.8% nationally.
PHL to STL on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airways | 85.3% | 64 min | 1.0% | 96 |
| Southwest Airlines | 78.6% | 74 min | 0.6% | 726 |
| American Airlines | 76.1% | 74 min | 1.4% | 647 |
| PSA Airlines | 76.0% | 69 min | 8.8% | 137 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PHL to STL
On-time arrival % by scheduled departure hour (local time), 3,202 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 94.7% | 0.0% | 151 |
| 7am–8am | 90.7% | 0.5% | 206 |
| 8am–9am | 90.4% | 0.5% | 368 |
| 9am–10am | 88.2% | 0.8% | 120 |
| 10am–11am | 86.1% | 0.0% | 202 |
| 11am–12pm | 82.1% | 1.5% | 324 |
| 12pm–1pm | 75.9% | 1.2% | 84 |
| 1pm–2pm | 79.6% | 0.9% | 109 |
| 2pm–3pm | 83.8% | 1.1% | 181 |
| 3pm–4pm | 65.7% | 1.8% | 220 |
| 4pm–5pm | 73.3% | 6.2% | 32 |
| 5pm–6pm | 76.2% | 2.6% | 151 |
| 6pm–7pm | 58.8% | 2.5% | 239 |
| 7pm–8pm | 68.3% | 2.3% | 474 |
| 8pm–9pm | 63.3% | 2.9% | 205 |
| 9pm–10pm | 73.9% | 7.4% | 95 |
| 10pm–11pm | 82.5% | 2.4% | 41 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PHL to STL
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 71.4% | -9.5 pts | 1.6% | 64 |
| Christmas & New Year (Dec 20 - Jan 3) | 73.2% | -7.7 pts | 0.0% | 139 |
| Summer peak (Jun 15 - Aug 15) | 67.8% | -13.1 pts | 3.1% | 609 |
| All other days | 80.9% | — | 1.4% | 2,390 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).