St. Louis (STL) to San Francisco (SFO): On-Time Performance
Data through July 2026
The calendar drives reliability on STL–SFO. October 2024 flights landed on schedule 89% of the time, but June 2026 dropped to 18% — a gap of 70 points. Across the full period the route averages 68% on-time against a national 78%. Morning departures also hold up better than evening ones (71% vs 63%), which matters most in the rough months.
- On-time
- 68%
- arrived <15 min late
- Avg delay
- 24 min
- completed flights
- Cancelled
- 0.6%
- Flights/day
- 2.1
- last 12 months
- Duration
- 4h 27m
- scheduled
- Distance
- 1,735 mi
Best airline from STL to SFO
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 74% | 22 min | 0.5% | 621 |
| SkyWest Airlines | 66% | 32 min | 1.8% | 273 |
| Southwest Airlines | 65% | 22 min | 0.1% | 732 |
Monthly on-time trend
Best time to fly from STL to SFO
Aim for departures around 7 a.m. (91% on-time); avoid 7 p.m. departures (39%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 66% | 25 min |
| Tuesdaybest | 74% | 21 min |
| Wednesday | 70% | 19 min |
| Thursday | 67% | 24 min |
| Friday | 68% | 25 min |
| Saturday | 73% | 21 min |
| Sunday | 62% | 29 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft24%
- Airline operations31%
- National airspace system42%
- Weather3%
Frequently asked questions
- How often are flights from STL to SFO delayed?
- 32% of STL–SFO flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 24 minutes.
- Which airline is most reliable from STL to SFO?
- United Airlines has the best on-time record on this route at 74%, based on 621 flights. 3 airlines flew STL–SFO frequently enough to compare in this period.
- What is the best time of day to fly from STL to SFO?
- Departures around 7 a.m. have the best record (91% on-time), while departures around 7 p.m. have the worst (39%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from STL to SFO?
- The scheduled STL–SFO flight time averages 4h 27m over 1,735 miles. Actual arrival times vary — flights on this route land 15+ minutes late 32% of the time.
- How often are STL to SFO flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to SFO?
- June 2026 was the roughest month in this dataset, with only 18% of arrivals on time. The best was October 2024 at 89%. If your dates are flexible, that 70-point gap is worth planning around.
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Based on 1,626 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.