Carrier route record

DLJFK→DEN

Delta Air Lines · New York to Denver

Flights: 937
Period: September 2025 to August 2026
Share of route: 61%
Carriers: 3

Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on JFK to DEN 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 77.3%. The late ones land a little over an hour behind schedule. That rests on 937 flights, with a median arrival 6 minutes early.

The US average over the same twelve months is 77.3%, so there is little to separate Delta on JFK to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

73.7%

Arrivals under 15 minutes late, of 911 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

2.56%

National rate is 1.89%

Whole route

71.4%

Every carrier on JFK to DEN, 1,531 flights

These figures cover 937 flights between September 2025 and August 2026. Beyond the headline rate, 9.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

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Carrier by carrier

Delta against every carrier on JFK to DEN

Delta flew 937 of the 1,531 flights on JFK to DEN, most of the route. Its 73.7% on time is 2 points better than the route as a whole, which runs 71.4%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 73.7% to Frontier at 67.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on JFK to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)	937	73.7%	69 min	2.56%	C
JetBlue Airways	545	67.9%	63 min	5.14%	C−
Frontier Airlinesthin sample	49	67.3%	124 min	0.00%	C+

Flight by flight

Delta flight numbers on JFK to DEN

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Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against half a point between the best and worst carrier.

5am–8am1 flights—
8am–11am362 flights82.3%
11am–2pm—
2pm–5pm159 flights64.5%
5pm–8pm157 flights63.6%
8pm–5am258 flights73.3%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 63.6% on time, against 82.3% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 362 flights scheduled in it.

Across the year

Delta on JFK to DEN through the year

Darker means more delays. Figures are on-time percentages.February best, August worst

August is the worst month at 59.3% on time, 31 points below February, the best at 90.4%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. April was the busiest month here, with 88 flights.

Across the week, Tuesday is the strongest day at 81.4% on time and Monday the weakest at 68.6%, a spread of 13 points.

Arrival by arrival

How late Delta on JFK to DEN runs when it is late

Delta on JFK to DEN often beats the schedule: 319 of 911 completed flights, 35%, arrived 15 minutes or more early. The 240 late arrivals split 77 under half an hour, 77 between 30 and 60 minutes, and 86 an hour or more.

15+ min early319 flights35.0%
Within 15 min352 flights38.6%
15–29 min late77 flights8.5%
30–59 min late77 flights8.5%
1–2 hours late51 flights5.6%
2+ hours late35 flights3.8%

Scale runs 0% to 100%.

Share of 911 completed flights by arrival against schedule.

43 of 183 late departures made up the time and arrived on time, 23% of them. In the other direction, 100 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 Delta on JFK to DEN

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 five of the five worst days.

The latest arrivals of Delta on JFK to DEN in the period
Date	Arrived late by	Largest filed cause
11 November 2025	12 hours 37 minutes	Carrier
31 October 2025	6 hours 1 minute	Carrier
10 October 2025	5 hours 49 minutes	Carrier
24 November 2025	5 hours 1 minute	Carrier
3 August 2026	4 hours 28 minutes	Carrier

Delay causes

Why Delta runs late on this route

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 17,000 reported delay minutes.

Carrier
39%
National Airspace System
36%
Late-arriving aircraft
22%
Extreme weather
2%

The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,567 of the 17,000 delay minutes reported here. The split is drawn from 16,629 reported delay minutes.

36% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 5,998 minutes out of 17,000, against a national NAS share of 21%.

Cancellations run at 2.56%, 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 stage length

What a delay here costs

9.4% 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 return leg is a different operation and performs like one: it runs 87.7% on time across 937 flights, 14 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 14 points of difference.

One caution: this is a thin sample. 937 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 Delta on JFK to DEN

Put together: treat all of this as provisional. 937 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 911 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures