Carrier route record
DLATL→BUF
Delta Air Lines · Atlanta to Buffalo
- Flights
- 1,250
- Period
- July 2025 to June 2026
- Share of route
- 83%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on ATL to BUF lands a B, 4 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,250 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, 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
81.2%
Arrivals under 15 minutes late, of 1,226 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
1.84%
National rate is 1.81%
Whole route
79.0%
Every carrier on ATL to BUF, 1,508 flights
These figures cover 1,250 flights between July 2025 and June 2026. The median arrival is 4 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
Delta against every carrier on ATL to BUF
Delta flew 1,250 of the 1,508 flights on ATL to BUF, most of the route. Its 81.2% on time is 2 points better than the route as a whole, which runs 79.0%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 81.2% 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) | 1,250 | 81.2% | 51 min | 1.84% | B |
| Frontier Airlinesthin sample | 257 | 68.5% | 81 min | 2.33% | C |
| Southwest Airlinesthin sample | 1 | 0.0% | 92 min | 0.00% | F+ |
Flight by flight
Delta flight numbers on ATL to BUF
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. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am346 flights92.0%
- 11am–2pm101 flights76.8%
- 2pm–5pm433 flights76.8%
- 5pm–8pm8 flights—
- 8pm–5am362 flights77.7%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 76.8% on time against 92.0% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 2pm–5pm window is the busiest, with 433 flights scheduled in it.
Across the year
Delta on ATL to BUF through the year
December is the weak month at 70.6% on time, against 91.6% in September. 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. October was the busiest month here, with 120 flights.
Across the week, Wednesday is the strongest day at 85.8% on time and Monday the weakest at 77.2%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 43% of the 12,000 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.
- 43%Carrier
- 27%Late-arriving aircraft
- 19%National Airspace System
- 11%Extreme weather
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 4,959 of the 12,000 delay minutes reported here. The split is drawn from 11,608 reported delay minutes.
Cancellations sit at 1.84% against a national 1.81%, which is ordinary. Diversions add another 0.08%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.8% 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.
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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 84.0% on time across 1,249 flights, within 3 points 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 1,250 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 December 70.6%, a swing of 21 points. If the dates move at all, move them out of December before you think about anything else. 1,226 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 BUF68.5%
- Delta Air Lines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- The best time of day to fly, according to 7.04 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.