Best Time to Fly STL to SAT: On-Time Stats by Hour & Airline
St Louis Lambert International → San Antonio International
Data through July 2026 · Last updated October 18, 2026
548 flights were scheduled from St. Louis (STL) to San Antonio (SAT) in the last 12 months, and 80.8% of those that flew arrived on time, 3.2 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Tuesday was the most reliable day (87% on time) and June the worst month (65%).
The cancellation rate was 0.2% (US average 1.8%).
STL to SAT 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 | 80.8% | 48 min | 0.2% | 548 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to SAT
On-time arrival % by scheduled departure hour (local time), 1,107 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | Limited data | 1 | |
| 8am–9am | 90.3% | 0.0% | 154 |
| 9am–10am | 88.0% | 0.8% | 126 |
| 10am–11am | 89.6% | 0.0% | 194 |
| 11am–12pm | 87.2% | 2.5% | 80 |
| 12pm–1pm | 87.5% | 0.0% | 41 |
| 1pm–2pm | Limited data | 15 | |
| 2pm–3pm | 81.0% | 0.0% | 58 |
| 3pm–4pm | Limited data | 27 | |
| 4pm–5pm | Limited data | 21 | |
| 5pm–6pm | 63.6% | 0.0% | 44 |
| 6pm–7pm | 68.1% | 0.0% | 69 |
| 7pm–8pm | 73.7% | 1.7% | 58 |
| 8pm–9pm | 71.4% | 2.3% | 43 |
| 9pm–10pm | 73.8% | 0.0% | 104 |
| 10pm–11pm | 68.1% | 1.4% | 72 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on STL to SAT
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 | 22 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 71.7% | -11.0 pts | 0.0% | 46 |
| Summer peak (Jun 15 - Aug 15) | 75.8% | -6.9 pts | 0.0% | 208 |
| All other days | 82.7% | — | 0.7% | 831 |
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).