Carrier route record
DLATL→BUF
Delta Air Lines · Atlanta to Buffalo
- Flights
- 1,255
- Period
- September 2025 to August 2026
- Share of route
- 82%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on ATL to BUF lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 1,255 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on ATL to BUF from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.1%
Arrivals under 15 minutes late, of 1,232 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
1.75%
National rate is 1.89%
Whole route
76.9%
Every carrier on ATL to BUF, 1,534 flights
These figures cover 1,255 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Delta against every carrier on ATL to BUF
Delta flew 1,255 of the 1,534 flights on ATL to BUF, most of the route. Its 79.1% on time is 2 points better than the route as a whole, which runs 76.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 79.1% to Southwest at 0.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 1,255 | 79.1% | 55 min | 1.75% | B |
| Frontier Airlinesthin sample | 278 | 67.2% | 84 min | 2.52% | C |
| Southwest Airlinesthin sample | 1 | 0.0% | 92 min | 0.00% | F+ |
Flight by flight
Delta flight numbers on ATL to BUF
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am346 flights88.5%
- 11am–2pm113 flights79.3%
- 2pm–5pm426 flights76.1%
- 5pm–8pm7 flights—
- 8pm–5am363 flights73.9%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 88.5% of the time, against 73.9% for the overnight window. That is 15 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 426 flights scheduled in it.
Across the year
Delta on ATL to BUF through the year
July is the worst month at 54.8% on time, 37 points below September, the best at 91.6%. 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. October was the busiest month here, with 120 flights.
Across the week, Wednesday is the strongest day at 87.0% on time and Sunday the weakest at 76.0%, a spread of 11 points.
Arrival by arrival
How late Delta on ATL to BUF runs when it is late
The 257 late arrivals split 102 under half an hour, 79 between 30 and 60 minutes, and 76 an hour or more.
- 15+ min early145 flights11.8%
- Within 15 min830 flights67.4%
- 15–29 min late102 flights8.3%
- 30–59 min late79 flights6.4%
- 1–2 hours late58 flights4.7%
- 2+ hours late18 flights1.5%
Scale runs 0% to 100%.
Share of 1,232 completed flights by arrival against schedule.
38 of 235 late departures made up the time and arrived on time, 16% of them. 60 flights left on time and still arrived late.
The worst days
Worst days for Delta on ATL to BUF
The latest arrival of the period was on 17 February 2026, 12 hours 5 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across February, August, July, December and January, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 February 2026 | 12 hours 5 minutes | Extreme weather |
| 11 August 2026 | 7 hours 33 minutes | Carrier |
| 3 July 2026 | 4 hours 27 minutes | National Airspace System |
| 7 December 2025 | 3 hours 7 minutes | Late-arriving aircraft |
| 24 January 2026 | 3 hours 4 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 14,000 reported delay minutes.
- 39%Carrier
- 32%Late-arriving aircraft
- 19%National Airspace System
- 9%Extreme weather
The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,560 of the 14,000 delay minutes reported here. The split is drawn from 14,127 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.5% on time here.
Cancellations sit at 1.75% against a national 1.89%, which is ordinary. Diversions add another 0.08%.
Connections and stage length
What a delay here costs
6.2% 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 about an hour, which a normal layover absorbs.
The 712 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 83.6% on time across 1,254 flights, 5 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 5 points of difference.
The sample behind these figures is 1,255 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.
What to do with this
Booking Delta on ATL to BUF
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 91.6% on time and July 54.8%, a swing of 37 points. If the dates move at all, move them out of July before you think about anything else. 1,232 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to BUF, every carrier
- Delta on BUF to ATL, the return leg
- Frontier Airlines on ATL to BUF67.2%
- Delta Air Lines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
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.