Best Time to Fly SAN to STL: On-Time Stats by Hour & Airline
San Diego International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
473 flights were scheduled from San Diego (SAN) to St. Louis (STL) in the last 12 months, and 74.8% of those that flew arrived on time, 2.8 points below the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Saturday was the most reliable day (87% on time) and July the worst month (62%).
The cancellation rate was 0.2% (US average 1.8%).
SAN 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 | 74.8% | 48 min | 0.2% | 473 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SAN to STL
On-time arrival % by scheduled departure hour (local time), 1,032 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 92.5% | 0.7% | 148 |
| 7am–8am | 86.7% | 0.9% | 114 |
| 8am–9am | 81.2% | 0.0% | 96 |
| 9am–10am | 83.2% | 0.0% | 143 |
| 10am–11am | 85.7% | 1.7% | 58 |
| 11am–12pm | 77.4% | 0.0% | 62 |
| 12pm–1pm | 78.6% | 0.0% | 56 |
| 1pm–2pm | 56.6% | 0.0% | 138 |
| 2pm–3pm | Limited data | 29 | |
| 3pm–4pm | Limited data | 1 | |
| 5pm–6pm | Limited data | 15 | |
| 6pm–7pm | 65.9% | 0.6% | 172 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SAN 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 | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 53.1% | -29.6 pts | 5.8% | 52 |
| Summer peak (Jun 15 - Aug 15) | 62.8% | -19.9 pts | 0.0% | 165 |
| All other days | 82.7% | — | 0.1% | 789 |
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).