Airports › St. Louis (STL) › August 2025
Airport month · August 2025
St Louis Lambert International in August 2025
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.
In August 2025, reporting carriers scheduled 5,539 domestic departures from St Louis Lambert International (STL). 76.9% left less than 15 minutes late and 78.7% reached their destination on time; 1.0% were cancelled.
Nationally that month, 76.8% of flights departed on time and 76.3% arrived on time, so STL departures were level with the national departure figure.
A year earlier, in August 2024, the airport had 5,749 departures with 78.7% leaving on time: a change of −1.8 points, with flights down 4%.
Flights arriving at STL that month were on time 78.0% of the time (5,538 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 45%, air carrier 31% and national aviation system 19%.
- On time 78.7%
- Arrived 15+ minutes late 20.0%
- Cancelled 1.0%
- Diverted 0.3%
August 2025 against a year earlier, the airport's year and the nation
| Measure | Aug 2025 | Aug 2024 | STL, 12 months to Jul 2026 | All reported flights, Aug 2025 |
|---|---|---|---|---|
| Departed on time | 76.9% | 78.7% | 74.1% | 76.8% |
| Arrived on time | 78.7% | 79.2% | 76.8% | 76.3% |
| Cancelled | 1.0% | 1.4% | 1.3% | 1.1% |
| Average departure delay (late minutes only) | 16.4 min | 14.4 min | 17.6 min | 17.6 min |
| Scheduled departures a day | 185 | 192 | 174 | 20,079 |
| Scheduled departures | 5,539 | 5,749 | 63,318 | 602,378 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| WN Southwest Airlines | 3,488 | 63% | 79.2% | 6.2 min | 0.7% |
| AA American Airlines | 552 | 10% | 75.9% | 16.8 min | 1.1% |
| DL Delta Air Lines | 494 | 9% | 89.3% | -8.5 min | 1.0% |
| OO SkyWest Airlines | 226 | 4% | 68.1% | 19.9 min | 1.8% |
| YX Republic Airline | 225 | 4% | 82.2% | 1.0 min | 2.7% |
| UA United Airlines | 199 | 4% | 67.8% | 22.7 min | 2.0% |
| MQ Envoy Air | 119 | 2% | 83.2% | 4.9 min | 1.7% |
| AS Alaska Airlines | 88 | 2% | 69.3% | 8.8 min | 0.0% |
| F9 Frontier Airlines | 87 | 2% | 67.8% | 34.9 min | 2.3% |
| NK Spirit Airlines | 34 | 1% | 79.4% | 24.2 min | 0.0% |
| OH PSA Airlines | 27 | 0% | 70.4% | 17.9 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| STL–ATL | St. Louis to Atlanta | 331 | 85.5% | -6.0 min | 1.5% |
| STL–DEN | St. Louis to Denver | 330 | 70.0% | 20.3 min | 0.0% |
| STL–ORD | St. Louis to Chicago | 255 | 66.3% | 19.6 min | 3.9% |
| STL–LGA | St. Louis to New York | 240 | 80.0% | 3.3 min | 1.7% |
| STL–DFW | St. Louis to Dallas/Fort Worth | 203 | 70.0% | 21.1 min | 2.5% |
| STL–DCA | St. Louis to Washington | 197 | 71.6% | 10.3 min | 1.0% |
| STL–MCO | St. Louis to Orlando | 184 | 73.4% | 8.8 min | 1.1% |
| STL–DTW | St. Louis to Detroit | 175 | 85.7% | 1.4 min | 0.0% |
| STL–DAL | St. Louis to Dallas | 173 | 74.6% | 12.5 min | 1.2% |
| STL–PHX | St. Louis to Phoenix | 165 | 74.5% | 18.8 min | 0.0% |
| STL–CLT | St. Louis to Charlotte | 162 | 82.7% | 9.9 min | 0.6% |
| STL–LAS | St. Louis to Las Vegas | 159 | 83.0% | 16.0 min | 1.3% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left STL on time in August 2025?
76.9% of 5,539 scheduled domestic departures left less than 15 minutes late, and 78.7% reached their destination on time. The national figures that month were 76.8% and 76.3%.
How does that compare with a year earlier?
In August 2024, 78.7% of 5,749 departures left on time and 1.4% were cancelled, against 76.9% and 1.0% in August 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for August 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for STL · methodology · corrections.