Flight number record
DL 1211
Delta Air Lines · Miami to Atlanta
- Route
- MIA → ATL
- Departs
- 07:10
- Flights
- 357
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1211, check with Delta Air Lines.
DL 1211 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 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 357 flights, with a median arrival 9 minutes early.
Set against the rest of the country, DL 1211's record is 15 points better than the US average of 77.3%. That gap is worth roughly 152 fewer late arrivals for every thousand flights.
Key figures
On time
92.5%
Arrivals under 15 minutes late, of 347 completed flights
Avg delay
97 min
Across delayed arrivals only, not all flights
Cancelled
2.52%
National rate is 1.89%
1 hour+ late
2.3%
National rate is 8.3%
These figures cover 357 flights between September 2025 and August 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.
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Schedule
When DL 1211 flies
DL 1211 flies MIA to ATL without a single fixed slot. Its most common scheduled departure was 07:10, used on 81 of 357 flights, with 07:05 (71 flights) and 07:00 (69 flights) next.
- Departs 07:1081 flights22.7%
- Departs 07:0571 flights19.9%
- Departs 07:0069 flights19.3%
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 07:10 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1211 runs 3 points better at 92.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 1211 next to MIA to ATL
Every carrier on MIA to ATL combined arrived on time 74.2% of the time across 6,271 flights, so DL 1211 is 18 points ahead of it. Delta flew 3,322 flights on the same city pair under all its flight numbers, including this one, and those ran 77.8% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 11 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1211thin sample | 357 | 92.5% | 97 min | 2.52% | A |
| All Delta Air Lines on MIA–ATL | 3,322 | 77.8% | 82 min | 1.78% | B |
| All carriers on MIA–ATL | 6,271 | 74.2% | 82 min | 1.59% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1211 quarter by quarter
Quarter by quarter DL 1211 held fairly steady: 93.3% in Jul–Sep 2025, 88.9% in Oct–Dec 2025, 92.0% in Jan–Mar 2026, 94.4% in Apr–Jun 2026 and 94.9% in Jul–Sep 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights93.3%
- Oct–Dec 202584 flights88.9%
- Jan–Mar 202690 flights92.0%
- Apr–Jun 202691 flights94.4%
- Jul–Sep 202662 flights94.9%
Scale runs 80% to 100%.
By weekday, DL 1211 did best on Wednesday at 98.0% on time and worst on Monday at 82.4%. Each day rests on about 51 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1211 runs when it is late
The 26 late arrivals split 11 under half an hour, 7 between 30 and 60 minutes, and 8 an hour or more.
- 15+ min early77 flights22.2%
- Within 15 min244 flights70.3%
- 15–29 min late11 flights3.2%
- 30–59 min late7 flights2.0%
- 1–2 hours late1 flights0.3%
- 2+ hours late7 flights2.0%
Scale runs 0% to 100%.
Share of 347 completed flights by arrival against schedule.
A late pushback is often recovered here: of 20 departures that left 15 minutes late or more, 6 still arrived on time. 12 flights left on time and still arrived late.
The worst days
Worst days for DL 1211
The latest arrival of the period was on 1 December 2025, 9 hours 10 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 1 December 2025 | 9 hours 10 minutes | Late-arriving aircraft |
| 31 August 2026 | 5 hours 20 minutes | Carrier |
| 16 March 2026 | 5 hours 15 minutes | National Airspace System |
| 17 March 2026 | 4 hours 57 minutes | Carrier |
| 23 September 2025 | 2 hours 58 minutes | Carrier |
Delay causes
Why DL 1211 runs late
Carrier accounts for 52% of the 2,532 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Carrier
- 27%National Airspace System
- 22%Late-arriving aircraft
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,315 of the 2,532 delay minutes reported here. The split is drawn from 2,532 delay minutes reported on DL 1211.
Cancellations run at 2.52%, against 1.89% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.3% land an hour or more behind schedule, against 8.3% 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.
Every one of the 357 flights under DL 1211 in the data flew MIA to ATL. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 357 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 1211
For a booking, the cancellation rate is the figure to plan around on DL 1211: 2.52% of its 357 scheduled flights did not operate. A late arrival costs an hour and a half, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- MIA to ATL, every carrier and departure
- ATL to MIA, the return direction
- Delta Air Lines 1510 on the same route83.5%
- Delta Air Lines 1332 on the same route73.7%
- Delta Air Lines 1261 on the same route93.1%
- Delta Air Lines 2836 on the same route87.0%
- Delta Air Lines 1386 on the same route58.1%
- Frontier Airlines 4405 on the same route54.8%
- 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
- What a cancellation rate actually tells you (and what it hides)
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.