Flight number record
DL 2511
Delta Air Lines · Rochester to Atlanta
- Route
- ROC → ATL
- Departs
- 12:26
- Flights
- 361
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 2511, check with Delta Air Lines.
DL 2511 lands a B, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 361 flights, with a median arrival 6 minutes early.
Key figures
On time
76.7%
Arrivals under 15 minutes late, of 352 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
1.94%
National rate is 1.89%
1 hour+ late
9.1%
National rate is 8.3%
These figures cover 361 flights between September 2025 and August 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 2511 flies
DL 2511 flies ROC to ATL without a single fixed slot. Its most common scheduled departure was 12:26, used on 73 of 361 flights.
- Departs 12:2673 flights20.2%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 12:26 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and DL 2511 runs level with that at 76.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 2511 next to ROC to ATL
Every carrier on ROC to ATL combined arrived on time 79.6% of the time across 1,043 flights, so DL 2511 is 3 points behind it. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 2511thin sample | 361 | 76.7% | 62 min | 1.94% | B |
| All Delta Air Lines on ROC–ATL | 1,043 | 79.6% | 76 min | 2.30% | B |
| All carriers on ROC–ATL | 1,043 | 79.6% | 76 min | 2.30% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 2511 quarter by quarter
DL 2511 did not run the same all year. Its best quarter was Jul–Sep 2025 at 96.7% on time and its weakest Jul–Sep 2026 at 63.9%, a swing of 33 points on roughly 72 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights96.7%
- Oct–Dec 202592 flights68.2%
- Jan–Mar 202688 flights75.6%
- Apr–Jun 202689 flights88.5%
- Jul–Sep 202662 flights63.9%
Scale runs 55% to 100%.
By weekday, DL 2511 ranged from 70.8% on Sunday to 80.8% on Tuesday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 2511 runs when it is late
DL 2511 often beats the schedule: 97 of 352 completed flights, 28%, arrived 15 minutes or more early. The 82 late arrivals split 25 under half an hour, 25 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early97 flights27.6%
- Within 15 min173 flights49.1%
- 15–29 min late25 flights7.1%
- 30–59 min late25 flights7.1%
- 1–2 hours late23 flights6.5%
- 2+ hours late9 flights2.6%
Scale runs 0% to 100%.
Share of 352 completed flights by arrival against schedule.
A late pushback is often recovered here: of 108 departures that left 15 minutes late or more, 34 still arrived on time. 8 flights left on time and still arrived late.
The worst days
Worst days for DL 2511
The latest arrival of the period was on 7 December 2025, 6 hours 43 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in December 2025.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 7 December 2025 | 6 hours 43 minutes | Late-arriving aircraft |
| 26 January 2026 | 4 hours 5 minutes | Extreme weather |
| 30 October 2025 | 3 hours 5 minutes | Late-arriving aircraft |
| 27 December 2025 | 3 hours 3 minutes | Late-arriving aircraft |
| 13 December 2025 | 2 hours 52 minutes | Late-arriving aircraft |
Delay causes
Why DL 2511 runs late
Late-arriving aircraft accounts for 43% of the 5,084 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Late-arriving aircraft
- 24%National Airspace System
- 22%Carrier
- 11%Extreme weather
Extreme weather accounts for 11% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 5,084 delay minutes reported on DL 2511.
Cancellations sit at 1.94% against a national 1.89%, which is ordinary. Diversions add another 0.55%.
Connections and routes
What a delay on this flight costs
9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 749 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.
DL 2511 is not only a ROC to ATL flight. It also flew ATL to ROC (361 flights, 83.0% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 361 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ATL to ROCthin sample | 361 | 83.0% | 45 min | 1.94% | B |
What to do with this
Booking DL 2511
For a booking, read DL 2511 as 76.7% on time with 1.94% cancelled over 361 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- ROC to ATL, every carrier and departure
- ATL to ROC, the return direction
- Delta Air Lines 1200 on the same route85.6%
- Delta Air Lines 2047 on the same route76.2%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.