Best Time to Fly STL to SAN: On-Time Stats by Hour & Airline
St Louis Lambert International → San Diego International
Data through July 2026 · Last updated October 18, 2026
473 flights were scheduled from St. Louis (STL) to San Diego (SAN) in the last 12 months, and 77.3% of those that flew arrived on time, in line with the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
March has been the best month (86% on time) and Monday the weakest day of the week (73%).
0.2% of flights were cancelled, versus 1.8% nationally.
STL to SAN 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 | 77.3% | 46 min | 0.2% | 473 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to SAN
On-time arrival % by scheduled departure hour (local time), 1,033 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 1 | |
| 6am–7am | 86.6% | 1.4% | 69 |
| 7am–8am | 96.4% | 0.0% | 55 |
| 8am–9am | 87.0% | 0.6% | 163 |
| 9am–10am | 86.7% | 0.0% | 90 |
| 10am–11am | 79.6% | 0.0% | 103 |
| 11am–12pm | 84.6% | 1.9% | 53 |
| 12pm–1pm | Limited data | 18 | |
| 1pm–2pm | 63.6% | 0.0% | 55 |
| 2pm–3pm | 82.7% | 0.0% | 52 |
| 3pm–4pm | 67.3% | 0.0% | 52 |
| 4pm–5pm | 76.7% | 0.0% | 104 |
| 5pm–6pm | 65.4% | 0.0% | 78 |
| 6pm–7pm | 54.9% | 0.0% | 51 |
| 7pm–8pm | 50.0% | 0.0% | 34 |
| 8pm–9pm | 69.8% | 2.2% | 46 |
| 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 STL to SAN
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) | 59.2% | -21.8 pts | 1.9% | 52 |
| Summer peak (Jun 15 - Aug 15) | 68.7% | -12.3 pts | 0.0% | 166 |
| All other days | 81.0% | — | 0.4% | 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).