St Louis Lambert International (STL) Delays and On-Time Departures
St. Louis, MO · ranked 289th of 333 airports for on-time departures
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, St. Louis (STL) had 63,318 scheduled departures and 75.1% of them left on time (US average 77.4%).
That ranks 289th of 333 US airports tracked on this site, with 1.3% of departures cancelled.
Among airlines at St. Louis (STL), Delta Air Lines left on time most often (87.4%).
Over 24 months, Tuesday was the most reliable day (83% on time) and July the worst month (68%).
Best time of day to fly out of St. Louis (STL)
On-time departure % by scheduled departure hour (local time), last 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 93.8% | 1.1% | 6,163 |
| 6am–7am | 92.1% | 1.6% | 9,420 |
| 7am–8am | 90.5% | 1.3% | 9,337 |
| 8am–9am | 87.9% | 0.8% | 9,564 |
| 9am–10am | 85.8% | 1.4% | 8,521 |
| 10am–11am | 85.6% | 0.8% | 9,276 |
| 11am–12pm | 82.4% | 1.6% | 5,968 |
| 12pm–1pm | 80.7% | 1.2% | 4,607 |
| 1pm–2pm | 75.2% | 1.2% | 6,910 |
| 2pm–3pm | 73.1% | 1.2% | 7,588 |
| 3pm–4pm | 71.3% | 1.7% | 7,287 |
| 4pm–5pm | 64.8% | 1.5% | 6,062 |
| 5pm–6pm | 69.4% | 1.8% | 8,458 |
| 6pm–7pm | 68.6% | 1.5% | 8,470 |
| 7pm–8pm | 61.4% | 1.4% | 6,799 |
| 8pm–9pm | 64.9% | 1.0% | 6,992 |
| 9pm–10pm | 59.3% | 1.1% | 4,006 |
| 10pm–11pm | 57.1% | 1.2% | 2,695 |
| 11pm–12am | Limited data | 19 | |
Airlines at STL ranked by on-time departures
Last 12 months. Airlines with fewer than 30 departures are marked “limited data”.
| Airline | On-time departures | On-time arrivals | Cancelled | Departures |
|---|---|---|---|---|
| Delta Air Lines | 87.4% | 88.2% | 1.6% | 5,325 |
| Alaska Airlines | 82.3% | 83.0% | 1.2% | 861 |
| Republic Airways | 81.6% | 79.5% | 4.5% | 3,172 |
| Envoy Air | 79.9% | 77.9% | 2.5% | 1,604 |
| American Airlines | 79.4% | 81.4% | 2.1% | 5,879 |
| United Airlines | 78.7% | 75.5% | 1.1% | 2,356 |
| SkyWest Airlines | 74.3% | 70.0% | 2.6% | 2,276 |
| PSA Airlines | 73.9% | 75.2% | 5.2% | 894 |
| Spirit Airlines | 73.4% | 73.1% | 1.2% | 80 |
| Frontier Airlines | 72.5% | 72.0% | 2.1% | 1,398 |
| Southwest Airlines | 71.9% | 76.8% | 0.7% | 39,473 |
80%+ good 70–79.9% fair <70% poor
Best day to fly out of STL
On-time departures by day, 24 months.
Best month to fly out of STL
On-time departures by month, 24 months.
Holiday travel at St. Louis (STL)
On-time departures during holiday periods compared with all other days, last 24 months.
| Period | On-time departures | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 70.4% | -9.5 pts | 1.4% | 2,510 |
| Christmas & New Year (Dec 20 - Jan 3) | 71.5% | -8.4 pts | 0.6% | 5,130 |
| Summer peak (Jun 15 - Aug 15) | 70.0% | -9.9 pts | 1.5% | 23,196 |
| All other days | 79.9% | — | 1.3% | 97,306 |
Monthly on-time departure trend at STL
On-time departure % each month, with the 12-month US average for reference.
Routes from St. Louis (STL)
Every route from STL with its own page, by number of flights (last 12 months, on-time arrivals).