Flight number record
DL 1257
Delta Air Lines · Atlanta to Baltimore
- Route
- ATL → BWI
- Departs
- 19:30
- Flights
- 296
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1257, check with Delta Air Lines.
DL 1257 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 296 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so DL 1257 runs 9 points behind the country as a whole. Across a thousand flights that is about 88 extra late arrivals.
Key figures
On time
68.5%
Arrivals under 15 minutes late, of 289 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
1.69%
National rate is 1.89%
1 hour+ late
11.8%
National rate is 8.3%
These figures cover 296 flights between September 2025 and August 2026. Beyond the headline rate, 11.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 1257 flies
DL 1257 flies ATL to BWI without a single fixed slot. Its most common scheduled departure was 19:30, used on 57 of 296 flights, with 20:27 (36 flights) next.
- Departs 19:3057 flights19.3%
- Departs 20:2736 flights12.2%
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 19:30 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and DL 1257 runs level with that at 68.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
DL 1257 next to ATL to BWI
Every carrier on ATL to BWI combined arrived on time 75.2% of the time across 5,402 flights, so DL 1257 is 7 points behind it. Delta flew 2,790 flights on the same city pair under all its flight numbers, including this one, and those ran 78.7% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1257thin sample | 296 | 68.5% | 63 min | 1.69% | C |
| All Delta Air Lines on ATL–BWI | 2,790 | 78.7% | 57 min | 2.04% | B |
| All carriers on ATL–BWI | 5,402 | 75.2% | 63 min | 2.26% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1257 quarter by quarter
DL 1257 did not run the same all year. Its best quarter was Oct–Dec 2025 at 82.9% on time and its weakest Jul–Sep 2026 at 41.2%, a swing of 42 points on roughly 59 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 flights73.3%
- Oct–Dec 202577 flights82.9%
- Jan–Mar 202649 flights55.3%
- Apr–Jun 202687 flights77.6%
- Jul–Sep 202653 flights41.2%
Scale runs 35% to 90%.
By weekday, DL 1257 did best on Tuesday at 78.9% on time and worst on Sunday at 57.8%. Each day rests on about 42 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1257 runs when it is late
The 91 late arrivals split 29 under half an hour, 28 between 30 and 60 minutes, and 34 an hour or more.
- 15+ min early18 flights6.2%
- Within 15 min180 flights62.3%
- 15–29 min late29 flights10.0%
- 30–59 min late28 flights9.7%
- 1–2 hours late25 flights8.7%
- 2+ hours late9 flights3.1%
Scale runs 0% to 100%.
Share of 289 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 83 departures that left 15 minutes late or more, only 4 made it up before arrival. 12 flights left on time and still arrived late.
The worst days
Worst days for DL 1257
The latest arrival of the period was on 30 November 2025, 4 hours 22 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 November 2025 | 4 hours 22 minutes | Carrier |
| 21 July 2026 | 4 hours 10 minutes | National Airspace System |
| 18 June 2026 | 3 hours 30 minutes | Carrier |
| 5 July 2026 | 3 hours 28 minutes | Carrier |
| 26 September 2025 | 2 hours 36 minutes | Carrier |
Delay causes
Why DL 1257 runs late
Carrier accounts for 48% of the 5,749 delay minutes carriers reported here, and the remaining four split what is left.
- 48%Carrier
- 26%National Airspace System
- 23%Late-arriving aircraft
- 3%Extreme weather
The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,750 of the 5,749 delay minutes reported here. The split is drawn from 5,749 delay minutes reported on DL 1257.
Cancellations sit at 1.69% against a national 1.89%, which is ordinary. Diversions add another 0.68%.
Connections and routes
What a delay on this flight costs
11.8% 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 577 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 same number turns up on one other city pair in the data, including LAS to SEA (24), but none flew often enough under DL 1257 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to BWI only.
One caution: this is a thin sample. 296 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.
What to do with this
Booking DL 1257
For a booking, DL 1257 is one of the weaker ways to fly ATL to BWI: 7 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- ATL to BWI, every carrier and departure
- BWI to ATL, the return direction
- Delta Air Lines 2928 on the same route69.9%
- Delta Air Lines 2711 on the same route89.3%
- Delta Air Lines 2590 on the same route79.0%
- Delta Air Lines 801 on the same route90.2%
- Delta Air Lines 1267 on the same route69.6%
- Delta Air Lines 2799 on the same route78.6%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) 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
- The best time of day to fly, according to 7.05 million flight records
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.