Airports › St. Louis (STL) › May 2026
Airport month · May 2026
St Louis Lambert International in May 2026
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 May 2026, reporting carriers scheduled 5,375 domestic departures from St Louis Lambert International (STL). 73.2% left less than 15 minutes late and 76.7% reached their destination on time; 0.8% were cancelled.
Nationally that month, 77.1% of flights departed on time and 77.6% arrived on time, so STL departures were 3.9 points below the national departure figure.
A year earlier, in May 2025, the airport had 5,628 departures with 76.0% leaving on time: a change of −2.8 points, with flights down 4%.
Flights arriving at STL that month were on time 76.6% of the time (5,375 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 47%, air carrier 27% and national aviation system 21%.
- On time 76.7%
- Arrived 15+ minutes late 22.2%
- Cancelled 0.8%
- Diverted 0.3%
May 2026 against a year earlier, the airport's year and the nation
| Measure | May 2026 | May 2025 | STL, 12 months to Jul 2026 | All reported flights, May 2026 |
|---|---|---|---|---|
| Departed on time | 73.2% | 76.0% | 74.1% | 77.1% |
| Arrived on time | 76.7% | 76.9% | 76.8% | 77.6% |
| Cancelled | 0.8% | 1.2% | 1.3% | 0.9% |
| Average departure delay (late minutes only) | 19.5 min | 15.7 min | 17.6 min | 16.0 min |
| Scheduled departures a day | 179 | 188 | 174 | 20,391 |
| Scheduled departures | 5,375 | 5,628 | 63,318 | 611,735 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| WN Southwest Airlines | 3,236 | 60% | 74.1% | 9.4 min | 0.4% |
| AA American Airlines | 543 | 10% | 80.3% | 13.9 min | 1.1% |
| DL Delta Air Lines | 496 | 9% | 89.5% | -4.2 min | 1.2% |
| YX Republic Airline | 246 | 5% | 82.9% | -0.5 min | 2.0% |
| OO SkyWest Airlines | 221 | 4% | 67.9% | 23.4 min | 2.3% |
| UA United Airlines | 191 | 4% | 78.5% | 9.8 min | 0.5% |
| F9 Frontier Airlines | 123 | 2% | 74.8% | 14.7 min | 1.6% |
| MQ Envoy Air | 123 | 2% | 82.1% | 4.5 min | 1.6% |
| AS Alaska Airlines | 100 | 2% | 82.0% | 0.9 min | 0.0% |
| OH PSA Airlines | 96 | 2% | 67.7% | 28.9 min | 4.2% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| STL–ATL | St. Louis to Atlanta | 330 | 80.3% | 2.3 min | 1.2% |
| STL–ORD | St. Louis to Chicago | 322 | 78.9% | 12.1 min | 1.9% |
| STL–DEN | St. Louis to Denver | 310 | 71.6% | 15.5 min | 0.3% |
| STL–LGA | St. Louis to New York | 234 | 72.2% | 8.6 min | 3.0% |
| STL–MCO | St. Louis to Orlando | 218 | 78.4% | 5.1 min | 0.5% |
| STL–DFW | St. Louis to Dallas/Fort Worth | 208 | 71.2% | 36.3 min | 4.3% |
| STL–PHX | St. Louis to Phoenix | 202 | 73.3% | 7.0 min | 0.5% |
| STL–DCA | St. Louis to Washington | 197 | 72.1% | 14.3 min | 1.5% |
| STL–DTW | St. Louis to Detroit | 179 | 81.0% | 2.7 min | 1.7% |
| STL–MSP | St. Louis to Minneapolis | 172 | 87.8% | -2.0 min | 0.0% |
| STL–LAS | St. Louis to Las Vegas | 171 | 78.9% | 7.5 min | 0.0% |
| STL–DAL | St. Louis to Dallas | 167 | 71.3% | 12.9 min | 1.8% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left STL on time in May 2026?
73.2% of 5,375 scheduled domestic departures left less than 15 minutes late, and 76.7% reached their destination on time. The national figures that month were 77.1% and 77.6%.
How does that compare with a year earlier?
In May 2025, 76.0% of 5,628 departures left on time and 1.2% were cancelled, against 73.2% and 0.8% in May 2026.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for May 2026; 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.