Best Time to Fly PIT to STL: On-Time Stats by Hour & Airline
Pittsburgh International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 81.3% of Pittsburgh (PIT) to St. Louis (STL) flights arrived on time (499 scheduled flights). That is 3.7 points above the national average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
November has been the best month (95% on time) and Sunday the weakest day of the week (76%).
0.2% of flights were cancelled, versus 1.8% nationally.
PIT 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 |
|---|---|---|---|---|
| Southwest Airlines | 81.3% | 51 min | 0.2% | 499 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PIT to STL
On-time arrival % by scheduled departure hour (local time), 880 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 1 | |
| 6am–7am | 96.1% | 0.0% | 127 |
| 7am–8am | 98.3% | 0.0% | 60 |
| 8am–9am | Limited data | 21 | |
| 9am–10am | 87.8% | 0.0% | 41 |
| 10am–11am | 93.5% | 1.1% | 93 |
| 11am–12pm | Limited data | 28 | |
| 12pm–1pm | 89.0% | 0.0% | 73 |
| 1pm–2pm | 85.1% | 0.0% | 114 |
| 2pm–3pm | 97.2% | 0.0% | 36 |
| 3pm–4pm | Limited data | 27 | |
| 4pm–5pm | 76.4% | 0.0% | 55 |
| 5pm–6pm | Limited data | 21 | |
| 6pm–7pm | Limited data | 14 | |
| 7pm–8pm | 63.2% | 0.0% | 57 |
| 8pm–9pm | 51.5% | 0.0% | 103 |
| 9pm–10pm | Limited data | 9 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PIT 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) | Limited data | 16 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 83.3% | -1.7 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 79.5% | -5.5 pts | 0.0% | 176 |
| All other days | 85.1% | — | 0.3% | 658 |
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).