Airports › Boise (BOI) › September 2025
Airport month · September 2025
Boise Air Terminal in September 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 September 2025, reporting carriers scheduled 1,924 domestic departures from Boise Air Terminal (BOI). 86.5% left less than 15 minutes late and 83.9% reached their destination on time; 0.4% were cancelled.
Nationally that month, 83.1% of flights departed on time and 82.8% arrived on time, so BOI departures were 3.4 points above the national departure figure.
A year earlier, in September 2024, the airport had 2,038 departures with 85.9% leaving on time: a change of +0.6 points, with flights down 6%.
Flights arriving at BOI that month were on time 84.2% of the time (1,924 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 40%, air carrier 32% and national aviation system 23%.
- On time 83.9%
- Arrived 15+ minutes late 15.5%
- Cancelled 0.4%
- Diverted 0.2%
September 2025 against a year earlier, the airport's year and the nation
| Measure | Sep 2025 | Sep 2024 | BOI, 12 months to Jul 2026 | All reported flights, Sep 2025 |
|---|---|---|---|---|
| Departed on time | 86.5% | 85.9% | 83.9% | 83.1% |
| Arrived on time | 83.9% | 85.5% | 82.9% | 82.8% |
| Cancelled | 0.4% | 0.1% | 0.5% | 0.5% |
| Average departure delay (late minutes only) | 9.6 min | 8.9 min | 12.2 min | 12.2 min |
| Scheduled departures a day | 64 | 68 | 65 | 18,748 |
| Scheduled departures | 1,924 | 2,038 | 23,701 | 562,439 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| OO SkyWest Airlines | 816 | 42% | 85.7% | 0.0 min | 0.2% |
| WN Southwest Airlines | 425 | 22% | 82.4% | 3.1 min | 0.5% |
| DL Delta Air Lines | 213 | 11% | 89.7% | -2.2 min | 0.0% |
| AS Alaska Airlines | 150 | 8% | 90.7% | -3.2 min | 1.3% |
| UA United Airlines | 150 | 8% | 80.7% | 1.1 min | 0.0% |
| AA American Airlines | 118 | 6% | 69.5% | 28.7 min | 1.7% |
| G4 Allegiant Air | 21 | 1% | 71.4% | 3.1 min | 0.0% |
| NK Spirit Airlines | 21 | 1% | 57.1% | 19.8 min | 0.0% |
| F9 Frontier Airlines | 10 | 1% | 90.0% | -18.9 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| BOI–SEA | Boise to Seattle | 330 | 83.6% | -2.6 min | 0.6% |
| BOI–DEN | Boise to Denver | 250 | 80.8% | 4.7 min | 0.0% |
| BOI–SLC | Boise to Salt Lake City | 150 | 91.3% | -2.8 min | 0.0% |
| BOI–PHX | Boise to Phoenix | 129 | 82.2% | 8.0 min | 0.8% |
| BOI–LAX | Boise to Los Angeles | 120 | 94.2% | -10.8 min | 0.0% |
| BOI–PDX | Boise to Portland | 120 | 95.0% | -3.4 min | 0.0% |
| BOI–LAS | Boise to Las Vegas | 115 | 73.0% | 11.3 min | 0.9% |
| BOI–SFO | Boise to San Francisco | 113 | 76.1% | 9.2 min | 0.0% |
| BOI–ORD | Boise to Chicago | 91 | 72.5% | 11.6 min | 0.0% |
| BOI–SAN | Boise to San Diego | 86 | 80.2% | 5.8 min | 2.3% |
| BOI–SMF | Boise to Sacramento | 73 | 89.0% | -1.0 min | 0.0% |
| BOI–DFW | Boise to Dallas/Fort Worth | 60 | 76.7% | 29.6 min | 3.3% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left BOI on time in September 2025?
86.5% of 1,924 scheduled domestic departures left less than 15 minutes late, and 83.9% reached their destination on time. The national figures that month were 83.1% and 82.8%.
How does that compare with a year earlier?
In September 2024, 85.9% of 2,038 departures left on time and 0.1% were cancelled, against 86.5% and 0.4% in September 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for September 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for BOI · methodology · corrections.