Carrier route record

DLJFK→DTW

Delta Air Lines · New York to Detroit

Flights: 776
Period: July 2025 to June 2026
Share of route: 64%
Carriers: 2

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

Delta on JFK to DTW lands a B, 4 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 776 flights, with a median arrival 17 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Delta on JFK to DTW from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

81.1%

Arrivals under 15 minutes late, of 756 completed flights

Avg delay

99 min

Across delayed arrivals only, not all flights

Cancelled

2.45%

National rate is 1.81%

Whole route

76.1%

Every carrier on JFK to DTW, 1,221 flights

These figures cover 776 flights between July 2025 and June 2026. Beyond the headline rate, 9.1% 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.

Carrier by carrier

Delta against every carrier on JFK to DTW

Delta flew 776 of the 1,221 flights on JFK to DTW, most of the route. Its 81.1% on time is 5 points better than the route as a whole, which runs 76.1%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 81.1% to JetBlue at 67.2%.

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 DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)	776	81.1%	99 min	2.45%	B
JetBlue Airways	445	67.2%	68 min	3.82%	C−

Flight by flight

Delta flight numbers on JFK to DTW

DL 244316:3080.8% · 317 flights

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 18 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am—
11am–2pm216 flights90.1%
2pm–5pm254 flights83.4%
5pm–8pm297 flights72.1%
8pm–5am9 flights—

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 90.1% on time, ahead of 5pm–8pm at 72.1%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5pm–8pm window is the busiest, with 297 flights scheduled in it.

Across the year

Delta on JFK to DTW through the year

Darker means more delays. Figures are on-time percentages.September best, July worst

July is the worst month at 66.3% on time, 23 points below September, the best at 89.7%. 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. August was the busiest month here, with 93 flights.

Across the week, Tuesday is the strongest day at 87.7% on time and Thursday the weakest at 74.1%. 14 points is a smaller lever than departure hour, but it is free.

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 14,000 reported delay minutes.

Late-arriving aircraft
38%
Carrier
36%
National Airspace System
22%
Extreme weather
4%

38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 14,000 reported delay minutes here, that single category outweighs weather by 9 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 14,214 reported delay minutes.

The largest share of delay minutes, 36%, 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 5,070 of the 14,000 delay minutes reported here.

Cancellations sit at 2.45% against a national 1.81%, which is ordinary. Diversions add another 0.13%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.1% 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.

The 509 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 return leg runs 81.7% on time across 778 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 776 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 DTW

Put together: treat all of this as provisional. 776 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 81.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 756 completed flights over 12 months sit behind that.

Where to go next

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