Flight number record
DL 1309
Delta Air Lines · Atlanta to Washington
- Route
- ATL → IAD
- Departs
- 19:51
- Flights
- 267
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1309, check with Delta Air Lines.
DL 1309 sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 267 flights, with a median arrival 1 minute late.
The national on-time rate over the same period is 77.6%, so DL 1309 runs 4 points behind the country as a whole. Across a thousand flights that is about 41 extra late arrivals.
Key figures
On time
73.5%
Arrivals under 15 minutes late, of 260 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
2.62%
National rate is 1.81%
1 hour+ late
8.1%
National rate is 8.1%
These figures cover 267 flights between July 2025 and June 2026. Beyond the headline rate, 8.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When DL 1309 flies
DL 1309 flies ATL to IAD without a single fixed slot. Its most common scheduled departure was 19:51, used on 49 of 267 flights, with 19:07 (31 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 19:5149 flights18.4%
- Departs 19:0731 flights11.6%
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 19:51 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 1309 runs 5 points better at 73.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
DL 1309 next to ATL to IAD
Every carrier on ATL to IAD combined arrived on time 76.5% of the time across 3,979 flights, so DL 1309 is 3 points behind it. Delta flew 2,219 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 81.6%, which this flight trails by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1309thin sample | 267 | 73.5% | 62 min | 2.62% | C |
| All Delta Air Lines on ATL–IAD | 2,219 | 77.8% | 78 min | 2.66% | B |
| All carriers on ATL–IAD | 3,979 | 76.5% | 81 min | 1.99% | B |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 1309 quarter by quarter
DL 1309 did not run the same all year. Its best quarter was Oct–Dec 2025 at 83.8% on time and its weakest Apr–Jun 2026 at 61.3%, a swing of 23 points on roughly 67 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 202542 flights65.0%
- Oct–Dec 202581 flights83.8%
- Jan–Mar 202668 flights80.0%
- Apr–Jun 202676 flights61.3%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1309 did best on Sunday at 77.8% on time and worst on Friday at 59.1%. Each day rests on about 38 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 1309 runs late
One category carries most of the weight here. Carrier accounts for 47% of the 4,254 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.
- 47%Carrier
- 22%National Airspace System
- 21%Late-arriving aircraft
- 9%Extreme weather
The largest share of delay minutes, 47%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,002 of the 4,254 delay minutes reported here. The split is drawn from 4,254 delay minutes reported on DL 1309.
Cancellations run at 2.62%, against 1.81% 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
8.1% 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 534 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 one other city pair in the data, including IAD to ATL (25), but none flew often enough under DL 1309 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to IAD only.
One caution: this is a thin sample. 267 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 1309
For a booking, the cancellation rate is the figure to plan around on DL 1309: 2.62% of its 267 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- ATL to IAD, every carrier and departure
- IAD to ATL, the return direction
- United Airlines 1831 on the same route77.2%
- Delta Air Lines 2549 on the same route75.0%
- United Airlines 632 on the same route86.3%
- United Airlines 2634 on the same route76.8%
- Frontier Airlines 1082 on the same route58.8%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Washington Dulles International (IAD) 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.