Airports › St. Louis (STL) › April 2025
Airport month · April 2025
St Louis Lambert International in April 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 April 2025, reporting carriers scheduled 5,439 domestic departures from St Louis Lambert International (STL). 79.9% left less than 15 minutes late and 79.9% reached their destination on time; 0.8% were cancelled.
Nationally that month, 80.6% of flights departed on time and 79.5% arrived on time, so STL departures were 0.7 points below the national departure figure.
A year earlier, in April 2024, the airport had 5,444 departures with 79.5% leaving on time: a change of +0.4 points, with flights down 0%.
Flights arriving at STL that month were on time 80.4% of the time (5,444 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 43%, air carrier 27% and national aviation system 25%.
- On time 79.9%
- Arrived 15+ minutes late 19.2%
- Cancelled 0.8%
- Diverted 0.1%
April 2025 against a year earlier, the airport's year and the nation
| Measure | Apr 2025 | Apr 2024 | STL, 12 months to Jul 2026 | All reported flights, Apr 2025 |
|---|---|---|---|---|
| Departed on time | 79.9% | 79.5% | 74.1% | 80.6% |
| Arrived on time | 79.9% | 80.9% | 76.8% | 79.5% |
| Cancelled | 0.8% | 0.6% | 1.3% | 0.8% |
| Average departure delay (late minutes only) | 13.6 min | 14.1 min | 17.6 min | 14.1 min |
| Scheduled departures a day | 181 | 182 | 174 | 19,465 |
| Scheduled departures | 5,439 | 5,444 | 63,318 | 583,950 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| WN Southwest Airlines | 3,504 | 64% | 80.3% | 4.4 min | 0.4% |
| AA American Airlines | 526 | 10% | 78.9% | 7.3 min | 1.7% |
| DL Delta Air Lines | 444 | 8% | 87.2% | 1.2 min | 0.7% |
| YX Republic Airline | 250 | 5% | 84.0% | -2.7 min | 1.2% |
| UA United Airlines | 232 | 4% | 68.1% | 27.1 min | 0.4% |
| MQ Envoy Air | 172 | 3% | 76.2% | 7.0 min | 2.9% |
| OH PSA Airlines | 90 | 2% | 68.9% | 25.6 min | 3.3% |
| OO SkyWest Airlines | 80 | 1% | 78.8% | 8.5 min | 0.0% |
| F9 Frontier Airlines | 69 | 1% | 63.8% | 33.1 min | 2.9% |
| AS Alaska Airlines | 59 | 1% | 88.1% | -7.9 min | 0.0% |
| NK Spirit Airlines | 13 | 0% | 84.6% | -4.1 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| STL–ATL | St. Louis to Atlanta | 285 | 84.2% | 0.0 min | 1.1% |
| STL–DEN | St. Louis to Denver | 284 | 67.3% | 23.5 min | 0.7% |
| STL–ORD | St. Louis to Chicago | 264 | 77.3% | 5.4 min | 1.5% |
| STL–LGA | St. Louis to New York | 225 | 84.9% | -1.9 min | 0.0% |
| STL–MCO | St. Louis to Orlando | 208 | 82.7% | 1.0 min | 1.0% |
| STL–PHX | St. Louis to Phoenix | 207 | 78.3% | 5.3 min | 0.0% |
| STL–DCA | St. Louis to Washington | 199 | 72.4% | 13.1 min | 1.0% |
| STL–DAL | St. Louis to Dallas | 181 | 81.2% | 2.3 min | 3.9% |
| STL–DFW | St. Louis to Dallas/Fort Worth | 180 | 66.1% | 31.4 min | 5.6% |
| STL–CLT | St. Louis to Charlotte | 177 | 82.5% | -1.6 min | 1.1% |
| STL–LAS | St. Louis to Las Vegas | 172 | 80.8% | 2.8 min | 0.6% |
| STL–MDW | St. Louis to Chicago | 160 | 83.1% | -1.9 min | 0.0% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left STL on time in April 2025?
79.9% of 5,439 scheduled domestic departures left less than 15 minutes late, and 79.9% reached their destination on time. The national figures that month were 80.6% and 79.5%.
How does that compare with a year earlier?
In April 2024, 79.5% of 5,444 departures left on time and 0.6% were cancelled, against 79.9% and 0.8% in April 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for April 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.