BOS · Boston Logan International Airport
Boston, MA. All airports.
Share of flights 15+ min late, by month
departures
arrivals
usual for the month (departures)
Jan 2015 → Jul 2026; gridlines 10/20/30/40%
Recent months — departures
| Month | Flights | Late 15+ | vs usual | Cancelled | Avg min | Main cause |
|---|---|---|---|---|---|---|
| Jul 2026 | 13,277 | 30.3% | +3.7 | 5.9% | 26 | Late aircraft |
| Jun 2026 | 12,683 | 21.6% | -3.4 | 1.8% | 17 | Late aircraft |
| May 2026 | 12,694 | 18.0% | -4.2 | 0.6% | 13 | Late aircraft |
| Apr 2026 | 12,626 | 20.2% | +1.7 | 0.3% | 14 | Late aircraft |
| Mar 2026 | 12,299 | 23.8% | +5.4 | 2.7% | 18 | Late aircraft |
| Feb 2026 | 10,232 | 23.8% | +2.5 | 8.2% | 19 | Late aircraft |
| Jan 2026 | 10,298 | 21.8% | +2.4 | 7.5% | 18 | Airline |
| Dec 2025 | 11,248 | 27.1% | +3.5 | 1.7% | 21 | Late aircraft |
| Nov 2025 | 11,385 | 20.2% | +6.2 | 2.8% | 17 | Late aircraft |
| Oct 2025 | 12,647 | 28.3% | +10.7 | 1.5% | 22 | Late aircraft |
| Sep 2025 | 11,597 | 26.1% | +10.0 | 1.4% | 21 | Late aircraft |
| Aug 2025 | 12,461 | 19.9% | -3.9 | 1.0% | 14 | Late aircraft |
| Jul 2025 | 12,912 | 27.8% | +5.4 | 4.1% | 24 | Late aircraft |
| Jun 2025 | 12,372 | 25.1% | +0.6 | 1.3% | 20 | Late aircraft |
| May 2025 | 12,547 | 24.2% | +3.7 | 0.8% | 19 | Late aircraft |
| Apr 2025 | 12,413 | 17.1% | -5.0 | 0.3% | 12 | Airline |
| Mar 2025 | 12,361 | 18.4% | -1.4 | 0.6% | 15 | Late aircraft |
| Feb 2025 | 10,292 | 22.3% | +1.0 | 2.5% | 19 | Air traffic |
| Jan 2025 | 10,624 | 15.2% | -5.8 | 2.4% | 11 | Air traffic |
| Dec 2024 | 11,778 | 23.6% | +4.8 | 1.4% | 18 | Late aircraft |
| Nov 2024 | 11,756 | 14.0% | -1.8 | 0.1% | 10 | Airline |
| Oct 2024 | 13,035 | 13.4% | -5.1 | 0.8% | 9 | Airline |
| Sep 2024 | 12,359 | 16.1% | -1.7 | 0.4% | 12 | Airline |
| Aug 2024 | 13,215 | 26.8% | +2.9 | 3.7% | 23 | Late aircraft |
Airlines here, Sep 2025 (departures)
| Airline | Flights | Late | Canc. |
|---|---|---|---|
| Allegiant | 51 | 9.8% | 0.0% |
| Frontier | 74 | 20.3% | 0.0% |
| Alaska | 245 | 20.9% | 0.4% |
| Envoy | 176 | 23.0% | 1.1% |
| JetBlue | 2,872 | 24.1% | 0.9% |
| Delta | 2,199 | 25.0% | 0.6% |
| United | 1,144 | 26.2% | 0.8% |
| American | 1,408 | 26.5% | 1.2% |
| Republic | 2,574 | 26.7% | 3.1% |
| Spirit | 215 | 28.4% | 3.3% |
| Southwest | 621 | 40.5% | 0.5% |
Airlines with 30+ departures that month.
Worst days on record
| Date | Flights | Late | Canc. |
|---|---|---|---|
| 2015-01-27 | 306 | — | 100% |
| 2022-01-29 | 246 | — | 100% |
| 2026-02-23 | 396 | — | 100% |
| 2018-03-13 | 424 | 0% | 100% |
| 2026-01-26 | 356 | 90% | 78% |
| 2015-02-15 | 266 | 82% | 86% |
| 2019-03-04 | 442 | 94% | 42% |
| 2015-02-02 | 323 | 62% | 89% |
| 2022-02-25 | 387 | 83% | 73% |
| 2019-01-20 | 290 | 75% | 78% |
| 2020-12-17 | 165 | 86% | 52% |
| 2018-01-04 | 355 | 7% | 92% |
Departures; ranked by share late or cancelled.
FAA programs, last 90 days
| Started (UTC) | What | Hours |
|---|---|---|
| 2026-10-19 23:00 | Departure delays | 6.2 |
| 2026-10-18 20:45 | Arrival delays | 4.5 |
| 2026-10-17 23:15 | Departure delays | 0.2 |
| 2026-10-17 21:45 | Departure delays | 0.5 |
| 2026-10-16 19:30 | Ground stop | 0.5 |
| 2026-10-16 12:15 | Ground delay program | 12.5 |
| 2026-10-15 23:30 | Departure delays | 2.8 |
| 2026-10-15 11:45 | Ground delay program | 7.5 |
| 2026-10-14 20:00 | Ground stop | 0.7 |
| 2026-10-14 18:29 | Ground delay program | 4.8 |