Airports › St. Louis (STL) › December 2025
Airport month · December 2025
St Louis Lambert International in December 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 December 2025, reporting carriers scheduled 5,359 domestic departures from St Louis Lambert International (STL). 69.4% left less than 15 minutes late and 73.3% reached their destination on time; 0.9% were cancelled.
Nationally that month, 72.0% of flights departed on time and 71.9% arrived on time, so STL departures were 2.6 points below the national departure figure.
A year earlier, in December 2024, the airport had 5,384 departures with 77.3% leaving on time: a change of −7.9 points, with flights down 0%.
Flights arriving at STL that month were on time 74.8% of the time (5,359 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 47%, air carrier 30% and national aviation system 18%.
- On time 73.3%
- Arrived 15+ minutes late 25.7%
- Cancelled 0.9%
- Diverted 0.1%
December 2025 against a year earlier, the airport's year and the nation
| Measure | Dec 2025 | Dec 2024 | STL, 12 months to Jul 2026 | All reported flights, Dec 2025 |
|---|---|---|---|---|
| Departed on time | 69.4% | 77.3% | 74.1% | 72.0% |
| Arrived on time | 73.3% | 80.7% | 76.8% | 71.9% |
| Cancelled | 0.9% | 0.4% | 1.3% | 1.5% |
| Average departure delay (late minutes only) | 21.4 min | 14.7 min | 17.6 min | 21.2 min |
| Scheduled departures a day | 179 | 180 | 174 | 19,410 |
| Scheduled departures | 5,359 | 5,384 | 63,318 | 582,304 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| WN Southwest Airlines | 3,453 | 64% | 73.7% | 10.1 min | 0.3% |
| DL Delta Air Lines | 430 | 8% | 77.9% | 8.8 min | 2.6% |
| AA American Airlines | 396 | 7% | 79.3% | 12.9 min | 0.3% |
| YX Republic Airline | 341 | 6% | 69.8% | 25.0 min | 2.6% |
| UA United Airlines | 180 | 3% | 71.7% | 20.6 min | 0.0% |
| OO SkyWest Airlines | 159 | 3% | 54.7% | 46.0 min | 3.8% |
| MQ Envoy Air | 126 | 2% | 74.6% | 10.3 min | 2.4% |
| F9 Frontier Airlines | 114 | 2% | 67.5% | 22.7 min | 1.8% |
| OH PSA Airlines | 96 | 2% | 78.1% | 11.8 min | 4.2% |
| AS Alaska Airlines | 54 | 1% | 53.7% | 23.7 min | 1.9% |
| NK Spirit Airlines | 10 | 0% | 30.0% | 65.1 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| STL–ATL | St. Louis to Atlanta | 311 | 79.1% | 4.1 min | 1.6% |
| STL–DEN | St. Louis to Denver | 266 | 68.8% | 20.5 min | 0.0% |
| STL–ORD | St. Louis to Chicago | 240 | 60.8% | 32.3 min | 2.9% |
| STL–LGA | St. Louis to New York | 230 | 66.1% | 21.8 min | 2.2% |
| STL–MCO | St. Louis to Orlando | 222 | 69.4% | 16.9 min | 0.5% |
| STL–PHX | St. Louis to Phoenix | 206 | 70.9% | 13.8 min | 0.0% |
| STL–DCA | St. Louis to Washington | 203 | 73.4% | 4.9 min | 2.0% |
| STL–DFW | St. Louis to Dallas/Fort Worth | 199 | 75.4% | 22.8 min | 1.0% |
| STL–LAS | St. Louis to Las Vegas | 186 | 75.8% | 11.6 min | 0.0% |
| STL–CLT | St. Louis to Charlotte | 166 | 78.3% | 15.7 min | 0.0% |
| STL–DTW | St. Louis to Detroit | 156 | 75.6% | 20.1 min | 3.2% |
| STL–DAL | St. Louis to Dallas | 153 | 76.5% | 8.1 min | 1.3% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left STL on time in December 2025?
69.4% of 5,359 scheduled domestic departures left less than 15 minutes late, and 73.3% reached their destination on time. The national figures that month were 72.0% and 71.9%.
How does that compare with a year earlier?
In December 2024, 77.3% of 5,384 departures left on time and 0.4% were cancelled, against 69.4% and 0.9% in December 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for December 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.