Flight number record

DL 424

Delta Air Lines · New York to Denver

Route: JFK → DEN
Departs: 19:55
Flights: 286
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 286 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.6%, so DL 424 runs 11 points behind the country as a whole. Across a thousand flights that is about 109 extra late arrivals.

On time

66.7%

Arrivals under 15 minutes late, of 279 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

2.45%

National rate is 1.81%

1 hour+ late

14.7%

National rate is 8.1%

These figures cover 286 flights between July 2025 and June 2026. Beyond the headline rate, 14.7% 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 424 flies

DL 424 flies JFK to DEN without a single fixed slot. Its most common scheduled departure was 19:55, used on 126 of 286 flights, with 19:00 (33 flights) and 19:10 (33 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 19:55126 flights44.1%
Departs 19:0033 flights11.5%
Departs 19:1033 flights11.5%

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 19:55 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 424 runs level with that at 66.7%. 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 424 next to JFK to DEN

Every carrier on JFK to DEN combined arrived on time 71.4% of the time across 1,572 flights, so DL 424 is 5 points behind it. Delta flew 978 flights on the same city pair under all its flight numbers, including this one, and those ran 73.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 15 points.

DL 424 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 424thin sample	286	66.7%	77 min	2.45%	C
All Delta Air Lines on JFK–DEN	978	73.2%	71 min	2.56%	C
All carriers on JFK–DEN	1,572	71.4%	67 min	2.54%	C
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 424 quarter by quarter

Quarter by quarter DL 424 held fairly steady: 67.5% in Jul–Sep 2025, 62.4% in Oct–Dec 2025 and 71.6% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202588 flights67.5%
Oct–Dec 202586 flights62.4%
Jan–Mar 202624 flights—
Apr–Jun 202688 flights71.6%

Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.

By weekday, DL 424 did best on Tuesday at 77.3% on time and worst on Thursday at 53.8%. Each day rests on about 41 flights, so a gap of 24 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 424 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 7,168 reported delay minutes.

Carrier
38%
Late-arriving aircraft
32%
National Airspace System
27%
Extreme weather
3%

The largest share of delay minutes, 38%, 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 2,723 of the 7,168 delay minutes reported here. The split is drawn from 7,168 delay minutes reported on DL 424.

Cancellations sit at 2.45% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.7% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 (34) 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. 286 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. 14.7% 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.

Where to go next

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.

Key figures