Route reliability record
BUF→BWI
Buffalo to Baltimore
- Flights
- 1,741
- Period
- July 2025 to June 2026
- Distance
- 281 mi
- Carriers
- 1
This route earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,741 BUF to BWI flights, with a median arrival 7 minutes early.
Best time to fly BUF to BWI: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 96.0% of the time and Wednesday flights 91.1%, against 86.5% for the route overall.
Set against the rest of the country, this route's record is 9 points better than the US average of 77.6%. That gap is worth roughly 89 fewer late arrivals for every thousand flights.
Key figures
On time
86.5%
Arrivals under 15 minutes late, of 1,709 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
1.61%
National rate is 1.81%
Best carrier
Southwest
86.5% on time across 1,741 flights
These figures cover 1,741 flights between July 2025 and June 2026. The median arrival is 7 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.
Carrier by carrier
Which airline is most reliable on BUF to BWI
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 | 1,741 | 86.5% | 57 min | 1.61% | A |
Best ways to make this trip
The most reliable ways to fly Buffalo to Baltimore
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. BUF → BWIBuffalo to Baltimore | Southwest Airlines | 85.1% | 86.5% | 1.61% | 5am–8am, Wed | — |
| 2. ROC → BWIRochester to Baltimore | Southwest Airlines | 81.4% | 82.4% | 1.27% | 5am–8am, Fri | — |
| 3. ROC → DCARochester to Washington | PSA Airlines | 61.1% | 65.0% | 5.94% | 5am–8am, Sat | — |
| 4. BUF → DCABuffalo to Washington | PSA Airlines | 59.2% | 63.1% | 6.18% | 5am–8am, Sat | — |
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 31 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–8am406 flights96.0%
- 8am–11am390 flights91.2%
- 11am–2pm389 flights88.5%
- 2pm–5pm368 flights79.7%
- 5pm–8pm187 flights64.6%
- 8pm–5am1 flights—
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.6% on time, against 96.0% 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 5am–8am window is the busiest, with 406 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 16 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.
July is the worst month at 76.8% on time, 16 points below September, the best at 93.2%. 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 91.1% on time and Monday the weakest at 83.4%. 8 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 49% of the 13,000 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.
- 49%Late-arriving aircraft
- 26%Carrier
- 24%National Airspace System
- 1%Extreme weather
49% 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 13,000 reported delay minutes here, that single category outweighs weather by 49 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 13,032 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 96.0% on time here.
Cancellations sit at 1.61% against a national 1.81%, which is ordinary. Diversions add another 0.23%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.1% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 76.4% on time across 1,739 flights, 10 points below 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 10 points of difference.
The sample behind these figures is 1,741 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 BWI 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 93.2% on time and July 76.8%, a swing of 16 points. If the dates move at all, move them out of July before you think about anything else. 1,709 completed flights over 12 months sit behind that.
Common questions
BUF to BWI questions
How often is BUF to BWI delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 13.5% of the 1,741 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is BUF to BWI compared with the rest of the country?
86.5% of flights arrive on time here against a national 77.6%, a difference of 9 points in its favour. That is worth a A on this site's grading scale.
What time of day has the fewest delays on BUF to BWI?
The 5am–8am departure window is the strongest at 96.0% on time. The 5pm–8pm window is the weakest at 64.6%, 31 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 July delays on BUF to BWI?
July is the weakest month at 76.8% on time, compared with 93.2% in September. Across the year that is 16 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
- BWI to BUF — the return legseparate record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- BUF to ORD, a related route74.0%
- ATL to BWI, a related route75.6%
- BUF to LGA, a related route78.2%
- Southwest Airlines on-time record86.5%
- 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 BWI and BWI 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.