St. Louis (STL) to San Diego (SAN): On-Time Performance
Data through May 2026
The calendar drives reliability on STL–SAN. November 2024 flights landed on schedule 94% of the time, but July 2025 dropped to 59% — a gap of 35 points. Across the full period the route averages 77% on-time against a national 78%. Morning departures also hold up better than evening ones (88% vs 57%), which matters most in the rough months.
- On-time
- 77%
- arrived <15 min late
- Avg delay
- 13 min
- completed flights
- Cancelled
- 0.4%
- Flights/day
- 1.3
- last 12 months
- Duration
- 3h 56m
- scheduled
- Distance
- 1,557 mi
Monthly on-time trend
Best time to fly from STL to SAN
Aim for departures around 7 a.m. (97% on-time); avoid 7 p.m. departures (50%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 72% | 17 min |
| Tuesdaybest | 86% | 7 min |
| Wednesday | 74% | 13 min |
| Thursday | 74% | 16 min |
| Friday | 75% | 15 min |
| Saturday | 83% | 10 min |
| Sunday | 76% | 14 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft49%
- Airline operations28%
- National airspace system17%
- Weather5%
Frequently asked questions
- How often are flights from STL to SAN delayed?
- 23% of STL–SAN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 13 minutes.
- What is the best time of day to fly from STL to SAN?
- Departures around 7 a.m. have the best record (97% on-time), while departures around 7 p.m. have the worst (50%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from STL to SAN?
- The scheduled STL–SAN flight time averages 3h 56m over 1,557 miles. Actual arrival times vary — flights on this route land 15+ minutes late 23% of the time.
- How often are STL to SAN flights cancelled?
- 0.4% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to SAN?
- July 2025 was the roughest month in this dataset, with only 59% of arrivals on time. The best was November 2024 at 94%. If your dates are flexible, that 35-point gap is worth planning around.
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Based on 1,077 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.