Airport month record
BOSDEC
Boston Logan International in December 2025
- Departures
- 11,248
- Month
- December 2025
- National, same month
- 73.2%
- Carriers
- 11
Historical statistics for December 2025, not live status or a forecast for this year’s December. For today’s conditions at BOS, see live FAA status.
BOS in December sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 73.2%. The late ones land a little over an hour behind schedule. That rests on 11,248 flights, of which United Airlines flew 970 at 77.9% on time.
United Airlines is the most reliable of the six carriers covered here at 77.9% on time across 970 flights.
Key figures
On time
68.7%
Arrivals under 15 minutes late, of 11,033 completed departures
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
1.69%
Nationally in December: 1.55%
Whole year
74.6%
BOS across all twelve months
These figures cover 11,248 departures from Boston Logan International in December 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
December next to BOS's other months
Against BOS's own year, December ran 6 points worse than the twelve-month rate of 74.6%, which makes it the worst of the twelve months in the data. Cancellations were unusually low for BOS in December, at 1.69% against 3.05% across the year. Either side of it, November ran 78.0% on time and January 73.6%, so a trip moved by a few weeks would have landed in a better stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| September 2025 | 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 (this page) | 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 December
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 points, against 18 points between the best and worst carrier.
- 5am–8am2,356 flights78.9%
- 8am–11am2,314 flights73.0%
- 11am–2pm1,853 flights68.4%
- 2pm–5pm1,955 flights63.7%
- 5pm–8pm1,976 flights61.1%
- 8pm–5am794 flights57.2%
Scale runs 50% to 85%.
The 8pm–5am window is where this operation falls apart: 57.2% on time, against 78.9% 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 5am–8am window is the busiest, with 2,356 flights scheduled in it.
Across the week, Wednesday is the strongest day at 79.8% on time and Sunday the weakest at 52.1%, a spread of 28 points.
Carrier by carrier
Which airlines ran best at BOS in December
The choice of carrier is not cosmetic here. United Airlines arrives on time 77.9% of the time; JetBlue Airways manages 60.0%. Sample sizes sit next to every figure, because a two-point gap across 3,066 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 3,066 | 60.0% | 70 min | 2.25% | D |
| Republic Airways | 2,554 | 74.6% | 71 min | 1.80% | C |
| Delta Air Lines | 2,241 | 66.9% | 72 min | 2.59% | C |
| American Airlines | 1,284 | 76.4% | 85 min | 0.31% | B+ |
| United Airlines | 970 | 77.9% | 72 min | 0.31% | B+ |
| Southwest Airlines | 567 | 71.6% | 50 min | 0.53% | C+ |
| Alaska Airlinesthin sample | 198 | 48.7% | 55 min | 1.01% | F |
| Spirit Airlinesthin sample | 127 | 59.8% | 91 min | 0.00% | D+ |
| Envoy Airthin sample | 114 | 69.0% | 64 min | 0.88% | C+ |
| Frontier Airlinesthin sample | 77 | 50.7% | 78 min | 5.19% | F− |
| Allegiant Airthin sample | 50 | 78.0% | 73 min | 0.00% | B+ |
The spread between United and JetBlue is 18 points, wide enough that it should decide the booking. On a hundred trips that is 18 more arrivals inside the on-time window.
Route by route
Busiest routes out of BOS in December
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| BOS to DCA · Washington | 689 | 69.9% | 73 min | 1.16% | C |
| BOS to ORD · Chicago | 556 | 69.7% | 86 min | 0.72% | C+ |
| BOS to LGA · New York | 506 | 75.9% | 87 min | 5.73% | B− |
| BOS to MCO · Orlando | 436 | 60.7% | 85 min | 1.61% | D |
| BOS to JFK · New York | 430 | 70.7% | 73 min | 3.95% | C− |
| BOS to ATL · Atlanta | 417 | 69.0% | 75 min | 2.64% | C |
| BOS to LAX · Los Angeles | 381 | 62.1% | 74 min | 1.31% | D |
| BOS to FLL · Fort Lauderdale | 366 | 53.1% | 83 min | 2.19% | F |
| BOS to PHL · Philadelphiathin sample | 364 | 76.1% | 80 min | 1.65% | B |
| BOS to SFO · San Franciscothin sample | 357 | 65.0% | 68 min | 0.84% | C+ |
| BOS to CLT · Charlottethin sample | 331 | 83.3% | 60 min | 0.30% | B+ |
| BOS to DEN · Denverthin sample | 301 | 73.5% | 53 min | 0.66% | C+ |
| BOS to DFW · Dallas-Fort Worththin sample | 290 | 71.7% | 87 min | 1.03% | C |
| BOS to MIA · Miamithin sample | 278 | 69.9% | 67 min | 2.16% | C |
| BOS to EWR · Newarkthin sample | 277 | 71.0% | 79 min | 1.81% | C |
| BOS to BWI · Baltimorethin sample | 275 | 79.0% | 54 min | 1.09% | B |
| BOS to RDU · Raleighthin sample | 249 | 69.9% | 76 min | 1.20% | C |
| BOS to TPA · Tampathin sample | 247 | 66.8% | 86 min | 2.83% | C |
| BOS to PBI · West Palm Beachthin sample | 240 | 53.6% | 73 min | 1.67% | F |
| BOS to RSW · Fort Myersthin sample | 233 | 59.6% | 65 min | 0.86% | D+ |
| BOS to BNA · Nashvillethin sample | 202 | 63.8% | 57 min | 1.49% | D |
| BOS to DTW · Detroitthin sample | 198 | 67.9% | 71 min | 1.01% | C |
| BOS to PHX · Phoenixthin sample | 179 | 69.7% | 44 min | 0.56% | C+ |
| BOS to IAH · Houstonthin sample | 175 | 77.7% | 44 min | 0.00% | B+ |
| BOS to SJU · San Juanthin sample | 170 | 58.6% | 80 min | 0.59% | D+ |
Delay causes
What held BOS up in December
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 246,000 reported delay minutes.
- 37%Late-arriving aircraft
- 31%Carrier
- 30%National Airspace System
- 3%Extreme weather
- 0%Security
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 246,000 reported delay minutes here, that single category outweighs weather by 12 to one. The split is drawn from 245,694 reported delay minutes.
Cancellations sit at 1.69% against a national 1.55%, which is ordinary. Diversions add another 0.22%.
12.0% of arrivals land a full hour or more behind schedule, against 10.0% 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 December
For a December trip through BOS: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 78.9% on time, and with 12.0% of arrivals an hour or more late, a connection here deserves more slack than the same trip in May would.
Related
Where to go next
- Boston Logan International (BOS), the whole year
- BOS in September75.7%
- BOS in October73.9%
- BOS in November78.0%
- 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.