Route reliability record
BOS→BUF
Boston to Buffalo
- Flights
- 1,235
- Period
- July 2025 to June 2026
- Distance
- 395 mi
- Carriers
- 3
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,235 BOS to BUF flights, with a median arrival 9 minutes early.
Best time to fly BOS to BUF: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 91.0% of the time and Saturday flights 82.3%, against 75.6% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.6%
Arrivals under 15 minutes late, of 1,208 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
2.19%
National rate is 1.81%
Best carrier
JetBlue
73.1% on time across 947 flights
These figures cover 1,235 flights between July 2025 and June 2026. Beyond the headline rate, 10.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on BOS to BUF
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 221 | 83.9% | 49 min | 1.36% | B |
| Envoy Airthin sample | 67 | 82.1% | 75 min | 0.00% | B+ |
| JetBlue Airways | 947 | 73.1% | 74 min | 2.53% | C |
Flight by flight
Flights on BOS to BUF
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am78 flights91.0%
- 8am–11am236 flights81.0%
- 11am–2pm233 flights84.3%
- 2pm–5pm258 flights78.3%
- 5pm–8pm295 flights61.1%
- 8pm–5am135 flights67.7%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 61.1% on time, against 91.0% 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 5pm–8pm window is the busiest, with 295 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 34 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 53.0% on time, against 86.7% in May. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. June was the busiest month here, with 169 flights.
Across the week, Saturday is the strongest day at 82.3% on time and Thursday the weakest at 67.7%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 64% of the 21,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 64%Late-arriving aircraft
- 23%Carrier
- 10%National Airspace System
- 3%Extreme weather
- 0%Security
64% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 21,000 reported delay minutes here, that single category outweighs weather by 22 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 20,948 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 91.0% on time here.
Cancellations sit at 2.19% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 395 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg runs 75.3% on time across 1,235 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,235 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in BUF after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 86.7% on time and December 53.0%, a swing of 34 points. If the dates move at all, move them out of December before you think about anything else. 1,208 completed flights over 12 months sit behind that.
Common questions
BOS to BUF questions
How often is BOS to BUF delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.4% of the 1,235 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is BOS to BUF compared with the rest of the country?
75.6% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BOS to BUF?
The 5am–8am departure window is the strongest at 91.0% on time. The 5pm–8pm window is the weakest at 61.1%, 30 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on BOS to BUF?
December is the weakest month at 53.0% on time, compared with 86.7% in May. Across the year that is 34 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- BUF to BOS — the return legseparate record
- Boston Logan International (BOS) delay statistics
- Republic Airways on BOS to BUF83.9%
- JetBlue Airways on BOS to BUF73.1%
- BOS to DCA, a related route74.0%
- ORD to BUF, a related route70.6%
- BOS to ORD, a related route72.7%
- Republic Airways on-time record83.9%
- Envoy Air on-time record82.1%
- JetBlue Airways on-time record73.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BOS to BUF and BUF to BOS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.