Best time to fly out of Boston Logan (BOS)
The early-flight folk wisdom holds up at Boston Logan: departures in the Before 6am band left on time 93.4% of the time, against 61.4% in the 8–10pm band. These are historical odds, not forecasts. The records say what happened on this schedule over three years; they know nothing about tomorrow’s thunderstorm.
Data through June 2026 · Bureau of Transportation Statistics
On-time rate by hour and day
On this page, “on time” means a departure that pushed back less than 15 minutes behind its scheduled time — the Bureau of Transportation Statistics definition, and the one airlines are held to.
| Departure time | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|---|
| Before 6am | 92 | 94 | 95 | 94 | 93 | 94 | 92 |
| 6–8am | 89 | 91 | 92 | 92 | 90 | 89 | 90 |
| 8–10am | 85 | 88 | 89 | 88 | 84 | 85 | 86 |
| 10am–12pm | 81 | 86 | 87 | 84 | 81 | 83 | 81 |
| 12–2pm | 78 | 82 | 83 | 79 | 77 | 81 | 78 |
| 2–4pm | 72 | 79 | 79 | 73 | 70 | 76 | 71 |
| 4–6pm | 67 | 74 | 73 | 64 | 64 | 72 | 64 |
| 6–8pm | 64 | 71 | 70 | 59 | 62 | 70 | 60 |
| 8–10pm | 63 | 69 | 67 | 57 | 58 | 63 | 55 |
| 10pm–12am | 64 | 67 | 74 | 61 | 65 | 58 | 59 |
The steadiest stretch at BOS was Before 6am — 93.4% of departures left on time across 13,903 flights. The weakest was 8–10pm at 61.4%. 6–8am departures from BOS left on time 90.3% of the time across 76,891 flights; 6–8pm departures, 64.6% across 49,091. That is a gap of 25.7 points, and it is the whole case for the early flight.
The year at BOS
July was the hard month at BOS: 71% of departures left on time, across 37,998 flights. November was the easy one at 84%. Each month pools three years of that month, so a single bad week does not decide it.
| Month | Share departures that left on time | Flights |
|---|---|---|
| January | 80.2% | 31,056 |
| February | 79.7% | 30,642 |
| March | 79.9% | 35,984 |
| April | 81.4% | 36,630 |
| May | 78.5% | 37,900 |
| June | 76.6% | 37,623 |
| July | 71% | 37,998 |
| August | 75.7% | 38,065 |
| September | 76.7% | 35,698 |
| October | 80.4% | 38,051 |
| November | 84% | 34,283 |
| December | 76.7% | 33,686 |
Airlines at BOS
Every airline with at least 100 departures from BOS, busiest first. These are that airline’s departures from this airport only — its record across the country sits on its own page.
| Airline | Left on time | Typical delay | Cancelled | Departures |
|---|---|---|---|---|
| JetBlue Airways | 74.1% | 73 min | 1.8% | 120,048 |
| Republic Airways | 83.4% | 69 min | 2.8% | 87,482 |
| Delta Air Lines | 79.7% | 77 min | 1.2% | 77,739 |
| American Airlines | 80% | 95 min | 1.8% | 49,706 |
| United Airlines | 82.5% | 80 min | 1.7% | 37,749 |
| Southwest Airlines | 71.6% | 59 min | 1.2% | 20,311 |
| Spirit Airlines | 68.2% | 75 min | 3.1% | 14,731 |
| Alaska Airlines | 77.2% | 59 min | 1.1% | 7,487 |
| Envoy Air | 79.8% | 77 min | 1.8% | 5,889 |
| Frontier Airlines | 73.9% | 78 min | 2.3% | 3,488 |
| Allegiant Air | 87.7% | 82 min | 1.2% | 1,723 |
| SkyWest Airlines | 79.6% | 101 min | 3.3% | 703 |
| Hawaiian Airlines | 75.8% | 111 min | 1.1% | 536 |
Spirit Airlines (through May 2026) and Hawaiian Airlines (through December 2025) stopped filing before June 2026. Their rows cover a shorter run of months than the rest of the table, so their figures are not set against the others anywhere on this page.
What delays out of BOS were put down to
Airlines file a reason with every arrival running 15 minutes late or more. Across 94,603 flights that departed BOS and ran 15 minutes late or more, the delay minutes break down with 38.2% put down to late-arriving aircraft and 32.8% to airline operations.
- Late-arriving aircraft 38.2%
- Airline operations 32.8%
- Air traffic & airport volume 25.8%
- Severe weather 3.1%
- Security 0.1%
Late-arriving aircraft is the knock-on category: the plane came in late, so it went out late again. It is why a 7am problem in Newark is still a problem in Denver at dinnertime, and why it is usually the biggest slice on the bar.
If you are connecting through BOS
Of 427,609 scheduled arrivals into BOS, 74.1% reached the gate less than 15 minutes behind schedule. Of the 102,165 arrivals that ran late, 47.4% were no more than 45 minutes behind — which is the difference between a tight connection and a new boarding pass.
Work out a specific layover — pick the airport and the minutes you have, and the tool reads the same arrival records back as a share.
Busiest routes out of BOS
Ranked by flights, with the share that arrived on time at the far end. Where a route carries enough flights for a page of its own the chip goes there; otherwise it goes to the destination airport.
- DCA 77.5% on time · 27,809 flights
- LGA 81.4% on time · 22,272 flights
- ORD 77.1% on time · 21,098 flights
- JFK 77.3% on time · 16,853 flights
- PHL 78.5% on time · 15,042 flights
- ATL 78.8% on time · 15,002 flights
- MCO 70.6% on time · 14,563 flights
- CLT 81.4% on time · 13,935 flights
- LAX 77.5% on time · 13,833 flights
- SFO 75% on time · 13,723 flights
BOS in one number
Boston Logan (BOS)
Rank 12 of 363 US airports by departures. Steadiest stretch of the day: Before 6am. Hardest month: July.
Questions about BOS
- What is the best time of day to fly out of Boston Logan?
- Before 6am. Departures in that band left on time 93.4% of the time across 13,903 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 8–10pm band was the weakest at 61.4%.
- Is the early flight out of BOS really more reliable?
- 6–8am departures from BOS left on time 90.3% of the time across 76,891 flights; 6–8pm departures, 64.6% across 49,091. That is a gap of 25.7 points, and it is the whole case for the early flight.
- What is the worst month to fly out of BOS?
- July: 71% of the departures that flew left on time, with 37,998 scheduled. November was the other end of the year at 84%. Each figure pools three years of that calendar month.
- Which airline is most on time at BOS?
- Allegiant Air — 87.7% of its 1,723 departures from BOS left on time. Southwest Airlines sat at the other end at 71.6% over 20,311 flights. Only airlines with at least 100 departures here are ranked. Airlines that stopped filing before June 2026 are left out of the ranking — their figures cover a shorter run of months than the rest of the table.
- How often are flights cancelled at BOS?
- 1.9% of scheduled departures were cancelled over July 2023 through June 2026. Cancellations are counted against everything scheduled, not against everything that flew — a rate that looks small still adds up to real people in a rebooking line.