Carrier route record

DLPHL→DTW

Delta Air Lines · Philadelphia to Detroit

Flights: 1,557
Period: July 2025 to June 2026
Share of route: 53%
Carriers: 7

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

Delta on PHL to DTW lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 1,557 flights, with a median arrival 14 minutes early.

Set against the rest of the country, Delta's PHL to DTW record is 5 points better than the US average of 77.6%. That gap is worth roughly 47 fewer late arrivals for every thousand flights.

On time

82.3%

Arrivals under 15 minutes late, of 1,524 completed flights

Avg delay

105 min

Across delayed arrivals only, not all flights

Cancelled

2.12%

National rate is 1.81%

Whole route

79.8%

Every carrier on PHL to DTW, 2,952 flights

These figures cover 1,557 flights between July 2025 and June 2026. Beyond the headline rate, 8.5% 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 PHL to DTW

Delta flew 1,557 of the 2,952 flights on PHL to DTW, most of the route. Its 82.3% on time is 3 points better than the route as a whole, which runs 79.8%. Ranked by on-time rate it is number two of seven carriers on the route, where the range runs from Spirit at 87.9% to SkyWest at 67.2%. Five 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 PHL to DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	133	87.9%	102 min	0.75%	A+
Delta Air Lines (this page)	1,557	82.3%	105 min	2.12%	B
American Airlinesthin sample	179	79.7%	72 min	0.56%	B+
PSA Airlines	845	76.3%	73 min	5.80%	B−
Republic Airwaysthin sample	112	74.3%	110 min	2.68%	C
Frontier Airlinesthin sample	57	67.9%	56 min	1.75%	C
SkyWest Airlinesthin sample	69	67.2%	223 min	2.90%	C

Flight by flight

Delta flight numbers on PHL to DTW

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 22 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–8am346 flights91.4%
8am–11am355 flights89.0%
11am–2pm328 flights85.7%
2pm–5pm1 flights—
5pm–8pm347 flights69.4%
8pm–5am180 flights71.0%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.4% of the time, against 69.4% for the evening window. That is 22 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 355 flights scheduled in it.

Across the year

Delta on PHL to DTW through the year

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

July is the worst month at 64.5% on time, 26 points below September, the best at 90.5%. 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. October was the busiest month here, with 146 flights.

Across the week, Tuesday is the strongest day at 89.0% on time and Sunday the weakest at 78.7%. 10 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 28,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
44%
Carrier
37%
National Airspace System
15%
Extreme weather
3%

44% 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 28,000 reported delay minutes here, that single category outweighs weather by 16 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 28,242 reported delay minutes.

The largest share of delay minutes, 37%, 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 11,000 of the 28,000 delay minutes reported here.

Cancellations sit at 2.12% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

8.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last close to two hours, which a normal layover absorbs.

At 453 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg runs 80.1% on time across 1,557 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,557 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking Delta on PHL to DTW

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 90.5% on time and July 64.5%, a swing of 26 points. If the dates move at all, move them out of July before you think about anything else. 1,524 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