Carrier route record
DLBUF→ATL
Delta Air Lines · Buffalo to Atlanta
- Flights
- 1,254
- 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 BUF to ATL lands a B, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 1,254 flights, with a median arrival 9 minutes early.
Set against the rest of the country, Delta's BUF to ATL record is 6 points better than the US average of 77.3%. That gap is worth roughly 63 fewer late arrivals for every thousand flights.
Key figures
On time
83.6%
Arrivals under 15 minutes late, of 1,225 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
1.91%
National rate is 1.89%
Whole route
80.4%
Every carrier on BUF to ATL, 1,533 flights
These figures cover 1,254 flights between September 2025 and August 2026. The median arrival is 9 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
Delta against every carrier on BUF to ATL
Delta flew 1,254 of the 1,533 flights on BUF to ATL, most of the route. Its 83.6% on time is 3 points better than the route as a whole, which runs 80.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Southwest at 100.0% to Frontier at 65.9%. 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 |
|---|---|---|---|---|---|
| Southwest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines (this page) | 1,254 | 83.6% | 56 min | 1.91% | B |
| Frontier Airlinesthin sample | 278 | 65.9% | 98 min | 2.52% | C |
Flight by flight
Delta flight numbers on BUF to ATL
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Departure window
When Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,254 flights.
- 5am–8am365 flights86.5%
- 8am–11am—
- 11am–2pm346 flights83.4%
- 2pm–5pm113 flights81.1%
- 5pm–8pm430 flights81.9%
- 8pm–5am—
Scale runs 75% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 86.5% on time for the 5am–8am window against 81.1% for 2pm–5pm. Worth taking if the schedule allows, not worth an extra connection. The 5pm–8pm window is the busiest, with 430 flights scheduled in it.
Across the year
Delta on BUF to ATL through the year
July is the worst month at 71.9% on time, 25 points below September, the best at 97.2%. 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. October was the busiest month here, with 120 flights.
Across the week, Wednesday is the strongest day at 90.4% on time and Sunday the weakest at 76.1%, a spread of 14 points.
Arrival by arrival
How late Delta on BUF to ATL runs when it is late
Delta on BUF to ATL often beats the schedule: 456 of 1,225 completed flights, 37%, arrived 15 minutes or more early. The 201 late arrivals split 82 under half an hour, 62 between 30 and 60 minutes, and 57 an hour or more.
- 15+ min early456 flights37.2%
- Within 15 min568 flights46.4%
- 15–29 min late82 flights6.7%
- 30–59 min late62 flights5.1%
- 1–2 hours late43 flights3.5%
- 2+ hours late14 flights1.1%
Scale runs 0% to 100%.
Share of 1,225 completed flights by arrival against schedule.
A late pushback is often recovered here: of 259 departures that left 15 minutes late or more, 100 still arrived on time. 42 flights left on time and still arrived late.
The worst days
Worst days for Delta on BUF to ATL
The latest arrival of the period was on 28 January 2026, 13 hours 48 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across January, February, July and March, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 January 2026 | 13 hours 48 minutes | Extreme weather |
| 18 February 2026 | 6 hours 34 minutes | Late-arriving aircraft |
| 3 July 2026 | 4 hours 41 minutes | Late-arriving aircraft |
| 1 February 2026 | 4 hours 22 minutes | Carrier |
| 3 March 2026 | 4 hours 9 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Late-arriving aircraft accounts for 44% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Late-arriving aircraft
- 28%Carrier
- 19%National Airspace System
- 10%Extreme weather
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 11,000 reported delay minutes here, that single category outweighs weather by 4 to one. The split is drawn from 11,176 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 86.5% on time here.
Cancellations sit at 1.91% against a national 1.89%, which is ordinary. Diversions add another 0.40%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.7% land an hour or more behind schedule, against 8.3% 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.
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 79.1% on time across 1,255 flights, 5 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 5 points of difference.
The sample behind these figures is 1,254 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 BUF to ATL
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 97.2% on time and July 71.9%, a swing of 25 points. If the dates move at all, move them out of July before you think about anything else. 1,225 completed flights over 12 months sit behind that.
Related
Where to go next
- BUF to ATL, every carrier
- Delta on ATL to BUF, the return leg
- Frontier Airlines on BUF to ATL65.9%
- Delta Air Lines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Why the first flight of the morning is statistically safest
- 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.