Route reliability record
BUF→ATL
Buffalo to Atlanta
- Flights
- 1,507
- Period
- July 2025 to June 2026
- Distance
- 712 mi
- Carriers
- 3
This route lands a B, 4 points better than the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,507 BUF to ATL flights, with a median arrival 9 minutes early.
Best time to fly BUF to ATL: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 85.6% of the time and Wednesday flights 90.1%, against 81.5% for the route overall.
The US average over the same twelve months is 77.6%, 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
81.5%
Arrivals under 15 minutes late, of 1,472 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
2.12%
National rate is 1.81%
Best carrier
Delta
84.0% on time across 1,249 flights
These figures cover 1,507 flights between July 2025 and June 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.
Carrier by carrier
Which airline is most reliable on BUF to ATL
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 | 1,249 | 84.0% | 60 min | 2.00% | B |
| Frontier Airlinesthin sample | 257 | 68.7% | 82 min | 2.72% | C |
Flight by flight
Flights on BUF to ATL
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Buffalo to Atlanta
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. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BUF → ATLBuffalo to Atlanta | Delta Air Lines | 82.3% | 84.0% | 2.00% | 11am–2pm, Wed | DL 1384 12:07 |
| 2. ROC → ATLRochester to Atlanta | Delta Air Lines | 79.0% | 81.1% | 2.60% | 5am–8am, Fri | DL 1200 06:00 |
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 10 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–8am365 flights85.6%
- 8am–11am11 flights—
- 11am–2pm522 flights82.2%
- 2pm–5pm155 flights75.5%
- 5pm–8pm452 flights79.2%
- 8pm–5am2 flights—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 85.6% of the time, against 75.5% for the afternoon window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 522 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
December is the weak month at 73.0% on time, against 96.0% 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. May was the busiest month here, with 149 flights.
Across the week, Wednesday is the strongest day at 90.1% on time and Sunday the weakest at 74.0%. 16 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 54% of the 18,000 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.
- 54%Late-arriving aircraft
- 25%Carrier
- 16%National Airspace System
- 6%Extreme weather
54% 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 18,000 reported delay minutes here, that single category outweighs weather by 9 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 18,108 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 85.6% on time here.
Cancellations sit at 2.12% against a national 1.81%, which is ordinary. Diversions add another 0.20%.
Connections and stage length
What a delay here actually costs
6.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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. 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 79.0% on time across 1,508 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 1,507 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 ATL 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 96.0% on time and December 73.0%, a swing of 23 points. If the dates move at all, move them out of December before you think about anything else. 1,472 completed flights over 12 months sit behind that.
Common questions
BUF to ATL questions
How often is BUF to ATL delayed?
Roughly one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 18.5% of the 1,507 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is BUF to ATL compared with the rest of the country?
81.5% of flights arrive on time here against a national 77.6%, a difference of 4 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BUF to ATL?
The 5am–8am departure window is the strongest at 85.6% on time. The 2pm–5pm window is the weakest at 75.5%, 10 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 December delays on BUF to ATL?
December is the weakest month at 73.0% on time, compared with 96.0% in September. Across the year that is 23 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
- ATL to BUF — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on BUF to ATL84.0%
- Frontier Airlines on BUF to ATL68.7%
- BUF to ORD, a related route74.0%
- LGA to ATL, a related route76.6%
- BUF to LGA, a related route78.2%
- Southwest Airlines on-time record100.0%
- Delta Air Lines on-time record84.0%
- Frontier Airlines on-time record68.7%
- 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 ATL and ATL 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.