Carrier route record
DLDTW→PHL
Delta Air Lines · Detroit to Philadelphia
- 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 DTW to PHL lands a B, 3 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,557 flights, with a median arrival 10 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on DTW to PHL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.1%
Arrivals under 15 minutes late, of 1,525 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
2.06%
National rate is 1.81%
Whole route
78.5%
Every carrier on DTW to PHL, 2,952 flights
These figures cover 1,557 flights between July 2025 and June 2026. Beyond the headline rate, 8.7% 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.
Carrier by carrier
Delta against every carrier on DTW to PHL
Delta flew 1,557 of the 2,952 flights on DTW to PHL, most of the route. Its 80.1% on time is 2 points better than the route as a whole, which runs 78.5%. Ranked by on-time rate it is first of seven carriers on the route, where the range runs from Delta at 80.1% to SkyWest at 61.5%. 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 1,557 | 80.1% | 77 min | 2.06% | B |
| PSA Airlines | 846 | 79.5% | 91 min | 5.20% | B− |
| Spirit Airlinesthin sample | 132 | 78.8% | 79 min | 0.00% | B+ |
| Republic Airwaysthin sample | 112 | 73.6% | 88 min | 5.36% | C− |
| American Airlinesthin sample | 179 | 72.3% | 129 min | 0.56% | C+ |
| Frontier Airlinesthin sample | 57 | 69.1% | 55 min | 3.51% | C− |
| SkyWest Airlinesthin sample | 69 | 61.5% | 93 min | 2.90% | D |
Flight by flight
Delta flight numbers on DTW to PHL
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–8am339 flights88.8%
- 8am–11am327 flights86.0%
- 11am–2pm1 flights—
- 2pm–5pm353 flights72.2%
- 5pm–8pm193 flights67.0%
- 8pm–5am344 flights81.6%
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 88.8% of the time, against 67.0% 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 2pm–5pm window is the busiest, with 353 flights scheduled in it.
Across the year
Delta on DTW to PHL through the year
December is the weak month at 67.5% on time, against 89.1% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. October was the busiest month here, with 146 flights.
Across the week, Saturday is the strongest day at 84.6% on time and Sunday the weakest at 75.5%. 9 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. Carrier accounts for 45% of the 23,000 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.
- 45%Carrier
- 31%National Airspace System
- 20%Late-arriving aircraft
- 4%Extreme weather
The largest share of delay minutes, 45%, 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 23,000 delay minutes reported here. The split is drawn from 23,422 reported delay minutes.
Cancellations sit at 2.06% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.7% 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 a little over an hour, 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 82.3% 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 DTW to PHL
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 89.1% on time and December 67.5%, a swing of 22 points. If the dates move at all, move them out of December before you think about anything else. 1,525 completed flights over 12 months sit behind that.
Related
Where to go next
- DTW to PHL, every carrier
- Delta on PHL to DTW, the return leg
- PSA Airlines on DTW to PHL79.5%
- Spirit Airlines on DTW to PHL78.8%
- Republic Airways on DTW to PHL73.6%
- American Airlines on DTW to PHL72.3%
- Delta Air Lines network-wide record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Philadelphia International (PHL) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.