Route reliability record
BWI→BUF
Baltimore to Buffalo
- Flights
- 1,727
- Period
- September 2025 to August 2026
- Distance
- 281 mi
- Carriers
- 1
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, about a point worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 1,727 BWI to BUF flights, with a median arrival 3 minutes early.
Best time to fly BWI to BUF: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 89.5% of the time and Wednesday flights 82.0%, against 75.9% for the route overall.
The US average over the same twelve months is 77.3%, 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
75.9%
Arrivals under 15 minutes late, of 1,686 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
2.14%
National rate is 1.89%
Best carrier
Southwest
75.9% on time across 1,727 flights
These figures cover 1,727 flights between September 2025 and August 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Which airline is most reliable on BWI 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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,727 | 75.9% | 52 min | 2.14% | B |
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Best ways to make this trip
The most reliable ways to fly Baltimore to Buffalo
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BWI → BUFBaltimore to Buffalo | Southwest Airlines | 74.3% | 75.9% | 2.14% | 5am–8am, Wed | — |
| 2. BWI → ROCBaltimore to Rochester | Southwest Airlines | 73.4% | 74.8% | 1.81% | 11am–2pm, Fri | — |
| 3. DCA → ROCWashington to Rochester | PSA Airlines | 60.7% | 64.9% | 6.46% | 8am–11am, Sat | — |
| 4. DCA → BUFWashington to Buffalo | PSA Airlines | 57.9% | 61.8% | 6.37% | 11am–2pm, Thu | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 28 points, against half a point between the best and worst carrier.
- 5am–8am328 flights89.5%
- 8am–11am261 flights89.5%
- 11am–2pm277 flights79.5%
- 2pm–5pm245 flights72.4%
- 5pm–8pm267 flights62.7%
- 8pm–5am349 flights61.6%
Scale runs 55% to 95%.
The 8pm–5am window is where this operation falls apart: 61.6% on time, against 89.5% 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 8pm–5am window is the busiest, with 349 flights scheduled in it.
Explore
Filter BWI to BUF by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On BWI to BUF, the best departure window is 5am–8am at 89.5% on time and the worst is 8pm–5am at 61.6%, a wide gap of 27.9 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am89.5%
- 8–11am89.5%
- 11am–2pm79.5%
- 2–5pm72.4%
- 5–8pm62.7%
- 8pm–5am61.6%
best all US flightsScale 55% to 95%.
Across the year
When delays peak on this route
This route's year swings by 25 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.
August is the worst month at 62.3% on time, 25 points below September, the best at 87.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 154 flights.
Across the week, Wednesday is the strongest day at 82.0% on time and Sunday the weakest at 70.0%, a spread of 12 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 46% of the 21,000 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Late-arriving aircraft
- 36%Carrier
- 15%National Airspace System
- 3%Extreme weather
- 1%Security
46% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 21,000 reported delay minutes here, that single category outweighs weather by 16 to one. The split is drawn from 21,101 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,586 of the 21,000 delay minutes reported here.
Cancellations sit at 2.14% against a national 1.89%, which is ordinary. Diversions add another 0.23%.
Connections and stage length
What a delay here actually costs
6.1% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
At 281 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 is a different operation and performs like one: it runs 87.0% on time across 1,728 flights, 11 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 11 points of difference.
The sample behind these figures is 1,727 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. September runs 87.1% on time and August 62.3%, a swing of 25 points. If the dates move at all, move them out of August before you think about anything else. 1,686 completed flights over 12 months sit behind that.
Common questions
BWI to BUF questions
How often is BWI 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 24.1% of the 1,727 flights in this analysis, against 22.7% nationally. Delayed flights are late by roughly 50 minutes on average.
How reliable is BWI to BUF compared with the rest of the country?
75.9% of flights arrive on time here against a national 77.3%, a difference of about a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BWI to BUF?
The 5am–8am departure window is the strongest at 89.5% on time. The 8pm–5am window is the weakest at 61.6%, 28 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 August delays on BWI to BUF?
August is the weakest month at 62.3% on time, compared with 87.1% in September. Across the year that is 25 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 BWI — the return legseparate record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- BWI to ATL, a related route79.9%
- ORD to BUF, a related route70.4%
- BWI to MCO, a related route75.5%
- Southwest Airlines on-time record75.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. BWI to BUF and BUF to BWI 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.