Best Time to Fly SFO to STL: On-Time Stats by Hour & Airline
San Francisco International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
760 flights were scheduled from San Francisco (SFO) to St. Louis (STL) in the last 12 months, and 64.1% of those that flew arrived on time, 13.5 points below the US average of 77.6%.
United Airlines was the most punctual of the 3 airlines on the route at 81.9%, while Southwest Airlines trailed at 45.4%.
January has been the best month (84% on time) and Monday the weakest day of the week (63%).
0.9% of flights were cancelled, versus 1.8% nationally.
SFO 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 |
|---|---|---|---|---|
| United Airlines | 81.9% | 54 min | 0.0% | 183 |
| SkyWest Airlines | 77.6% | 85 min | 2.5% | 235 |
| Southwest Airlines | 45.4% | 60 min | 0.3% | 342 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SFO to STL
On-time arrival % by scheduled departure hour (local time), 1,595 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 1 | |
| 6am–7am | 96.7% | 0.0% | 30 |
| 7am–8am | Limited data | 19 | |
| 8am–9am | 90.3% | 3.1% | 32 |
| 9am–10am | 91.4% | 1.2% | 84 |
| 10am–11am | 65.5% | 0.7% | 461 |
| 11am–12pm | 69.0% | 0.0% | 358 |
| 12pm–1pm | 61.2% | 0.4% | 252 |
| 1pm–2pm | 51.7% | 0.0% | 117 |
| 4pm–5pm | 67.3% | 3.6% | 56 |
| 6pm–7pm | 82.9% | 2.4% | 84 |
| 10pm–11pm | Limited data | 25 | |
| 11pm–12am | 74.3% | 2.6% | 76 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SFO 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) | 62.5% | -8.2 pts | 0.0% | 33 |
| Christmas & New Year (Dec 20 - Jan 3) | 55.9% | -14.8 pts | 1.7% | 60 |
| Summer peak (Jun 15 - Aug 15) | 62.4% | -8.4 pts | 0.8% | 266 |
| All other days | 70.7% | — | 0.7% | 1,236 |
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).