Airport month record
BOSSEP
Boston Logan International in September 2025
- Departures
- 11,597
- Month
- September 2025
- National, same month
- 83.4%
- Carriers
- 11
Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at BOS, see live FAA status.
BOS in September sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 8 points worse than the national rate of 83.4%. The late ones land a little over an hour behind schedule. That rests on 11,597 flights, of which JetBlue Airways flew 2,872 at 81.4% on time.
JetBlue Airways is the most reliable of the six carriers covered here at 81.4% on time across 2,872 flights.
Key figures
On time
75.7%
Arrivals under 15 minutes late, of 11,418 completed departures
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.35%
Nationally in September: 0.51%
Whole year
74.6%
BOS across all twelve months
These figures cover 11,597 departures from Boston Logan International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
September next to BOS's other months
Against BOS's own year, September ran about a point better than the twelve-month rate of 74.6%, which makes it number five of twelve months, best first. Cancellations were unusually low for BOS in September, at 1.35% against 3.05% across the year.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| September 2025 (this page) | 11,597 | 75.7% | 73 min | 1.35% | B |
| October 2025 | 12,647 | 73.9% | 75 min | 1.51% | C |
| November 2025 | 11,385 | 78.0% | 75 min | 2.76% | B |
| December 2025 | 11,248 | 68.7% | 71 min | 1.69% | C |
| January 2026 | 10,298 | 73.6% | 78 min | 7.50% | C− |
| February 2026 | 10,232 | 74.8% | 73 min | 8.15% | C− |
| March 2026 | 12,299 | 74.1% | 69 min | 2.69% | C |
| April 2026 | 12,626 | 79.3% | 62 min | 0.31% | B+ |
| May 2026 | 12,694 | 79.4% | 60 min | 0.61% | B+ |
| June 2026 | 12,683 | 76.6% | 72 min | 1.77% | B |
| July 2026 | 13,277 | 70.8% | 83 min | 5.92% | C− |
| August 2026 | 13,188 | 69.8% | 82 min | 3.60% | C− |
Departure window
The best time of day to leave BOS in September
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 42 points, against 20 points between the best and worst carrier.
- 5am–8am2,285 flights91.2%
- 8am–11am2,478 flights89.2%
- 11am–2pm1,851 flights82.5%
- 2pm–5pm2,179 flights67.5%
- 5pm–8pm2,064 flights53.3%
- 8pm–5am740 flights49.7%
Scale runs 40% to 95%.
The 8pm–5am window is where this operation falls apart: 49.7% on time, against 91.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 2,478 flights scheduled in it.
Across the week, Tuesday is the strongest day at 85.9% on time and Thursday the weakest at 59.4%, a spread of 27 points.
Carrier by carrier
Which airlines ran best at BOS in September
The choice of carrier is not cosmetic here. JetBlue Airways arrives on time 81.4% of the time; Southwest Airlines manages 61.7%. Sample sizes sit next to every figure, because a two-point gap across 621 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 2,872 | 81.4% | 63 min | 0.87% | B+ |
| Republic Airways | 2,574 | 74.5% | 65 min | 3.11% | C− |
| Delta Air Lines | 2,199 | 75.4% | 83 min | 0.59% | B+ |
| American Airlines | 1,408 | 73.0% | 81 min | 1.21% | C |
| United Airlines | 1,144 | 74.6% | 77 min | 0.79% | C+ |
| Southwest Airlines | 621 | 61.7% | 74 min | 0.48% | D+ |
| Alaska Airlinesthin sample | 245 | 78.9% | 78 min | 0.41% | B+ |
| Spirit Airlinesthin sample | 215 | 70.2% | 74 min | 3.26% | C− |
| Envoy Airthin sample | 176 | 79.9% | 70 min | 1.14% | B |
| Frontier Airlinesthin sample | 74 | 78.4% | 53 min | 0.00% | B+ |
| Allegiant Airthin sample | 51 | 88.2% | 135 min | 0.00% | A+ |
Republic Airways cancels 3.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Busiest routes out of BOS in September
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| BOS to DCA · Washington | 762 | 69.1% | 64 min | 1.84% | C |
| BOS to ORD · Chicago | 660 | 67.9% | 80 min | 0.61% | C+ |
| BOS to LGA · New York | 634 | 77.5% | 65 min | 3.15% | B− |
| BOS to JFK · New York | 545 | 79.3% | 61 min | 2.57% | B |
| BOS to PHL · Philadelphia | 428 | 76.9% | 67 min | 1.87% | B |
| BOS to SFO · San Francisco | 408 | 81.4% | 80 min | 0.00% | B+ |
| BOS to ATL · Atlanta | 401 | 82.8% | 66 min | 0.25% | B+ |
| BOS to LAX · Los Angelesthin sample | 364 | 79.1% | 85 min | 0.00% | B+ |
| BOS to EWR · Newarkthin sample | 336 | 70.9% | 83 min | 2.98% | C |
| BOS to DEN · Denverthin sample | 333 | 72.5% | 71 min | 0.30% | C+ |
| BOS to CLT · Charlottethin sample | 318 | 71.8% | 79 min | 1.89% | C |
| BOS to DFW · Dallas-Fort Worththin sample | 313 | 71.0% | 95 min | 2.56% | C |
| BOS to MCO · Orlandothin sample | 288 | 75.5% | 63 min | 0.69% | B+ |
| BOS to BWI · Baltimorethin sample | 288 | 75.0% | 87 min | 1.39% | B |
| BOS to RDU · Raleighthin sample | 256 | 73.5% | 82 min | 1.17% | C |
| BOS to BNA · Nashvillethin sample | 256 | 71.8% | 93 min | 0.78% | C+ |
| BOS to DTW · Detroitthin sample | 245 | 85.2% | 69 min | 0.41% | A+ |
| BOS to FLL · Fort Lauderdalethin sample | 232 | 65.6% | 74 min | 2.16% | C |
| BOS to SEA · Seattlethin sample | 229 | 84.2% | 94 min | 0.00% | B+ |
| BOS to MIA · Miamithin sample | 224 | 79.4% | 75 min | 0.45% | B+ |
| BOS to TPA · Tampathin sample | 197 | 75.9% | 72 min | 1.02% | B |
| BOS to PIT · Pittsburghthin sample | 197 | 73.6% | 57 min | 2.03% | C |
| BOS to CMH · Columbusthin sample | 180 | 76.4% | 65 min | 1.11% | B |
| BOS to MSP · Minneapolisthin sample | 176 | 80.7% | 88 min | 0.00% | B+ |
| BOS to CLE · Clevelandthin sample | 170 | 80.1% | 77 min | 2.35% | B |
Delay causes
What held BOS up in September
Late-arriving aircraft accounts for 56% of the 202,000 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Late-arriving aircraft
- 24%Carrier
- 17%National Airspace System
- 3%Extreme weather
- 0%Security
56% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 202,000 reported delay minutes here, that single category outweighs weather by 18 to one. The split is drawn from 201,756 reported delay minutes.
Cancellations sit at 1.35% against a national 0.51%, which is ordinary. Diversions add another 0.19%.
9.9% of arrivals land a full hour or more behind schedule, against 5.4% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
What to do with this
Flying from BOS in September
For a September trip through BOS: expect 75.7% on time and 1.35% cancelled, going by September 2025. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- Boston Logan International (BOS), the whole year
- BOS in October73.9%
- BOS in November78.0%
- BOS in December68.7%
- BOS in January73.6%
- BOS in February74.8%
- BOS in March74.1%
- BOS in April79.3%
- BOS in May79.4%
- BOS in June76.6%
- BOS in July70.8%
- BOS in August69.8%
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.