Flight number record
DL 1249
Delta Air Lines · Miami to Atlanta
- Route
- MIA → ATL
- Departs
- 06:00
- Flights
- 274
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1249, check with Delta Air Lines.
DL 1249 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 274 flights, with a median arrival 14 minutes early.
Set against the rest of the country, DL 1249's record is 15 points better than the US average of 77.6%. That gap is worth roughly 150 fewer late arrivals for every thousand flights.
Key figures
On time
92.6%
Arrivals under 15 minutes late, of 269 completed flights
Avg delay
99 min
Across delayed arrivals only, not all flights
Cancelled
1.82%
National rate is 1.81%
1 hour+ late
3.3%
National rate is 8.1%
These figures cover 274 flights between July 2025 and June 2026. The median arrival is 14 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.
Schedule
When DL 1249 flies
DL 1249 flies MIA to ATL without a single fixed slot. Its most common scheduled departure was 06:00, used on 159 of 274 flights, with 05:50 (38 flights) and 05:30 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 06:00159 flights58.0%
- Departs 05:5038 flights13.9%
- Departs 05:3036 flights13.1%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1249 runs 3 points better at 92.6%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
DL 1249 next to MIA to ATL
Every carrier on MIA to ATL combined arrived on time 73.7% of the time across 6,223 flights, so DL 1249 is 19 points ahead of it. Delta flew 3,300 flights on the same city pair under all its flight numbers, including this one, and those ran 76.7% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 11 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1249thin sample | 274 | 92.6% | 99 min | 1.82% | A |
| All Delta Air Lines on MIA–ATL | 3,300 | 76.7% | 83 min | 1.39% | B |
| All carriers on MIA–ATL | 6,223 | 73.7% | 80 min | 1.41% | C |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 1249 quarter by quarter
DL 1249 did not run the same all year. Its best quarter was Apr–Jun 2026 at 98.9% on time and its weakest Oct–Dec 2025 at 74.5%, a swing of 24 points on roughly 69 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 202540 flights94.9%
- Oct–Dec 202553 flights74.5%
- Jan–Mar 202690 flights95.5%
- Apr–Jun 202691 flights98.9%
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1249 did best on Saturday at 97.3% on time and worst on Thursday at 84.6%. Each day rests on about 39 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 1249 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 1,985 reported delay minutes.
- 36%Carrier
- 34%National Airspace System
- 29%Late-arriving aircraft
34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 677 minutes out of 1,985, against a national NAS share of 21%. The split is drawn from 1,985 delay minutes reported on DL 1249.
Cancellations sit at 1.82% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.3% 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 594 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 same number turns up on four other city pairs in the data, including ATL to MIA (41), GEG to SLC (4) and MSP to MCI (1), but none flew often enough under DL 1249 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to MIA to ATL only.
One caution: this is a thin sample. 274 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 1249
For a booking, read DL 1249 as 92.6% on time with 1.82% cancelled over 274 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- MIA to ATL, every carrier and departure
- ATL to MIA, the return direction
- Delta Air Lines 1261 on the same route92.0%
- Delta Air Lines 1510 on the same route78.9%
- Delta Air Lines 1332 on the same route73.9%
- Delta Air Lines 2836 on the same route84.6%
- Delta Air Lines 1211 on the same route92.2%
- Delta Air Lines 1386 on the same route58.4%
- Miami International (MIA) delay statistics
- 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
- The best time of day to fly, according to 7.04 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.