Flight number record
DL 424
Delta Air Lines · New York to Denver
- Route
- JFK → DEN
- Departs
- 19:50
- Flights
- 287
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 424, check with Delta Air Lines.
DL 424 draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 287 flights, with a median arrival 5 minutes early.
The national on-time rate over the same period is 77.3%, so DL 424 runs 11 points behind the country as a whole. Across a thousand flights that is about 109 extra late arrivals.
Key figures
On time
66.4%
Arrivals under 15 minutes late, of 280 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
2.44%
National rate is 1.89%
1 hour+ late
14.3%
National rate is 8.3%
These figures cover 287 flights between September 2025 and August 2026. Beyond the headline rate, 14.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 424 flies
DL 424 flies JFK to DEN without a single fixed slot. Its most common scheduled departure was 19:50, used on 86 of 287 flights, with 19:55 (66 flights) and 19:10 (33 flights) next.
- Departs 19:5086 flights30.0%
- Departs 19:5566 flights23.0%
- Departs 19:1033 flights11.5%
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 19:50 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and DL 424 runs level with that at 66.4%. 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 424 next to JFK to DEN
Every carrier on JFK to DEN combined arrived on time 71.4% of the time across 1,531 flights, so DL 424 is 5 points behind it. Delta flew 937 flights on the same city pair under all its flight numbers, including this one, and those ran 73.7% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 424thin sample | 287 | 66.4% | 78 min | 2.44% | C |
| All Delta Air Lines on JFK–DEN | 937 | 73.7% | 69 min | 2.56% | C |
| All carriers on JFK–DEN | 1,531 | 71.4% | 69 min | 3.40% | C− |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 424 quarter by quarter
DL 424 did not run the same all year. Its best quarter was Apr–Jun 2026 at 71.6% on time and its weakest Jul–Sep 2026 at 59.6%, a swing of 12 points on roughly 96 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 202527 flights—
- Oct–Dec 202586 flights62.4%
- Jan–Mar 202624 flights—
- Apr–Jun 202688 flights71.6%
- Jul–Sep 202662 flights59.6%
Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.
By weekday, DL 424 did best on Tuesday at 78.6% on time and worst on Thursday at 57.5%. Each day rests on about 41 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 424 runs when it is late
DL 424 often beats the schedule: 97 of 280 completed flights, 35%, arrived 15 minutes or more early. The 94 late arrivals split 22 under half an hour, 32 between 30 and 60 minutes, and 40 an hour or more.
- 15+ min early97 flights34.6%
- Within 15 min89 flights31.8%
- 15–29 min late22 flights7.9%
- 30–59 min late32 flights11.4%
- 1–2 hours late24 flights8.6%
- 2+ hours late16 flights5.7%
Scale runs 0% to 100%.
Share of 280 completed flights by arrival against schedule.
21 of 81 late departures made up the time and arrived on time, 26% of them. In the other direction, 34 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 424
The latest arrival of the period was on 11 November 2025, 12 hours 37 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 November 2025 | 12 hours 37 minutes | Carrier |
| 6 September 2025 | 4 hours 25 minutes | Late-arriving aircraft |
| 26 March 2026 | 4 hours 22 minutes | Carrier |
| 5 August 2026 | 3 hours 57 minutes | Carrier |
| 27 December 2025 | 3 hours 47 minutes | Late-arriving aircraft |
Delay causes
Why DL 424 runs late
Carrier accounts for 44% of the 7,345 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Carrier
- 29%National Airspace System
- 26%Late-arriving aircraft
- 1%Extreme weather
The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,211 of the 7,345 delay minutes reported here. The split is drawn from 7,345 delay minutes reported on DL 424.
Cancellations sit at 2.44% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
14.3% 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.
At 1,626 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The same number turns up on three other city pairs in the data, including ILM to ATL (62), DEN to JFK (33) and ATL to GPT (4), but none flew often enough under DL 424 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to JFK to DEN only.
One caution: this is a thin sample. 287 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 424
For a booking, DL 424 is a flight to put a long connection behind. 14.3% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- JFK to DEN, every carrier and departure
- DEN to JFK, the return direction
- Delta Air Lines 532 on the same route82.4%
- JetBlue Airways 97 on the same route54.6%
- John F. Kennedy International (JFK) 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
- How often a connection fails at the major US hubs
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.