Route reliability record
BUF→BOS
Buffalo to Boston
- 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 BUF to BOS flights, with a median arrival 8 minutes early.
Best time to fly BUF to BOS: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 88.7% of the time and Saturday flights 80.0%, against 75.3% 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
75.3%
Arrivals under 15 minutes late, of 1,209 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
2.11%
National rate is 1.81%
Best carrier
JetBlue
73.0% on time across 948 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 BUF to BOS
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 | 85.3% | 64 min | 1.36% | A |
| Envoy Airthin sample | 66 | 74.2% | 62 min | 0.00% | C+ |
| JetBlue Airways | 948 | 73.0% | 75 min | 2.43% | C |
Flight by flight
Flights on BUF to BOS
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–8am287 flights88.7%
- 8am–11am290 flights81.2%
- 11am–2pm233 flights74.3%
- 2pm–5pm184 flights68.7%
- 5pm–8pm222 flights58.3%
- 8pm–5am19 flights—
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 58.3% on time, against 88.7% 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 290 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.
January is the weak month at 55.3% on time, against 89.7% 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 80.0% on time and Thursday the weakest at 70.5%. 10 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 48% of the 22,000 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.
- 48%Late-arriving aircraft
- 37%National Airspace System
- 15%Carrier
- 0%Extreme weather
48% 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 22,000 reported delay minutes here, that single category outweighs weather by 48 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 21,885 reported delay minutes.
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 8,078 minutes out of 22,000, against a national NAS share of 21%.
Cancellations sit at 2.11% 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 75.6% 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 BOS 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 89.7% on time and January 55.3%, a swing of 34 points. If the dates move at all, move them out of January before you think about anything else. 1,209 completed flights over 12 months sit behind that.
Common questions
BUF to BOS questions
How often is BUF to BOS 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 24.7% 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 BUF to BOS compared with the rest of the country?
75.3% 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 BUF to BOS?
The 5am–8am departure window is the strongest at 88.7% on time. The 5pm–8pm window is the weakest at 58.3%, 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 January delays on BUF to BOS?
January is the weakest month at 55.3% on time, compared with 89.7% 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
- BOS to BUF — the return legseparate record
- Boston Logan International (BOS) delay statistics
- Republic Airways on BUF to BOS85.3%
- JetBlue Airways on BUF to BOS73.0%
- BUF to ORD, a related route74.0%
- DCA to BOS, a related route71.4%
- BUF to LGA, a related route78.2%
- Republic Airways on-time record85.3%
- Envoy Air on-time record74.2%
- JetBlue Airways on-time record73.0%
- 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. BUF to BOS and BOS to BUF 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.