Flight number record
DL 956
Delta Air Lines · Atlanta to Denver
- Route
- ATL → DEN
- Departs
- 22:59
- Flights
- 283
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 956, check with Delta Air Lines.
DL 956 sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 283 flights, with a median arrival 3 minutes early.
Key figures
On time
75.4%
Arrivals under 15 minutes late, of 276 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
2.12%
National rate is 1.89%
1 hour+ late
7.2%
National rate is 8.3%
These figures cover 283 flights between September 2025 and August 2026. The median arrival is 3 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 956 flies
DL 956 flies ATL to DEN without a single fixed slot. Its most common scheduled departure was 22:59, used on 67 of 283 flights, with 22:40 (59 flights) next.
- Departs 22:5967 flights23.7%
- Departs 22:4059 flights20.8%
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 22:59 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and DL 956 runs 5 points better at 75.4%. 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 956 next to ATL to DEN
Every carrier on ATL to DEN combined arrived on time 78.0% of the time across 5,594 flights, so DL 956 is 3 points behind it. Delta flew 2,807 flights on the same city pair under all its flight numbers, including this one, and those ran 79.0% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 956thin sample | 283 | 75.4% | 52 min | 2.12% | B |
| All Delta Air Lines on ATL–DEN | 2,807 | 79.0% | 52 min | 1.21% | B |
| All carriers on ATL–DEN | 5,594 | 78.0% | 61 min | 1.11% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 956 quarter by quarter
DL 956 did not run the same all year. Its best quarter was Jan–Mar 2026 at 86.2% on time and its weakest Oct–Dec 2025 at 66.7%, a swing of 20 points on roughly 71 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 202512 flights—
- Oct–Dec 202542 flights66.7%
- Jan–Mar 202684 flights86.2%
- Apr–Jun 202683 flights74.4%
- Jul–Sep 202662 flights71.7%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, DL 956 did best on Tuesday at 83.9% on time and worst on Sunday at 60.4%. Each day rests on about 40 flights, so a gap of 24 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 956 runs when it is late
DL 956 often beats the schedule: 69 of 276 completed flights, 25%, arrived 15 minutes or more early. The 68 late arrivals split 28 under half an hour, 20 between 30 and 60 minutes, and 20 an hour or more.
- 15+ min early69 flights25.0%
- Within 15 min139 flights50.4%
- 15–29 min late28 flights10.1%
- 30–59 min late20 flights7.2%
- 1–2 hours late18 flights6.5%
- 2+ hours late2 flights0.7%
Scale runs 0% to 100%.
Share of 276 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 51 departures that left 15 minutes late or more, only 6 made it up before arrival. In the other direction, 23 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for DL 956
The latest arrival of the period was on 11 December 2025, 8 hours 7 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 December 2025 | 8 hours 7 minutes | Carrier |
| 1 June 2026 | 2 hours 29 minutes | Carrier |
| 18 July 2026 | 1 hour 59 minutes | Carrier |
| 14 June 2026 | 1 hour 55 minutes | Late-arriving aircraft |
| 7 December 2025 | 1 hour 52 minutes | Late-arriving aircraft |
Delay causes
Why DL 956 runs late
Carrier accounts for 50% of the 3,518 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Carrier
- 27%Late-arriving aircraft
- 21%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 50%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,753 of the 3,518 delay minutes reported here. The split is drawn from 3,518 delay minutes reported on DL 956.
Cancellations sit at 2.12% against a national 1.89%, which is ordinary. Diversions add another 0.35%.
Connections and routes
What a delay on this flight costs
7.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
The 1,199 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 283 flights under DL 956 in the data flew ATL to DEN. 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. 283 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 956
For a booking, read DL 956 as 75.4% on time with 2.12% cancelled over 283 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- ATL to DEN, every carrier and departure
- DEN to ATL, the return direction
- Delta Air Lines 519 on the same route66.7%
- United Airlines 235 on the same route78.5%
- Delta Air Lines 746 on the same route67.8%
- Delta Air Lines 706 on the same route84.7%
- Frontier Airlines 3293 on the same route81.2%
- Delta Air Lines 530 on the same route80.5%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Denver International (DEN) 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
- Worst months to fly in the US, ranked by the data
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.