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Delta Air Lines / DTW → PHL

DL 1391 on time

Delta Air Lines 1391: Detroit to Philadelphia at 10:00 a.m.; Philadelphia to Detroit at 5:18 p.m. (past 12 months). Figures below the title are for DTW → PHL, its busiest leg

On time
67%
239 flights · likely 60–72%
Cancelled
2.1%
of scheduled flights
Typical arrival
−1 min
median vs schedule
When late
+94 min
average delay
Similar flights
68%
DL, same route & hour

About 1 in 3 DL 1391 flights from Detroit arrived 15+ minutes late, diverted or cancelled over the past year (33%); 2.1% were cancelled. The typical flight landed 1 minutes early.

DL 1391: DTW → PHL

Scheduled to leave Detroit at 10:00 a.m. local time. Over the past year it arrived on time 67% of the time (239 flights), in line with other DL flights on the route at that hour (68%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Jan 2026: 74% on time (27 flights)74JanFeb 2026: 75% on time (28 flights)75FebMar 2026: 77% on time (31 flights)77MarApr 2026: 77% on time (30 flights)77AprMay 2026: 71% on time (31 flights)71MayJun 2026: 60% on time (30 flights)60JunJul 2026: 45% on time (31 flights)45JulAug 2026: 55% on time (31 flights)55Aug

By day of week

DayFlightsOn time
Monday3551%
Tuesday3474%
Wednesday3474%
Thursday3471%
Friday3468%
Saturday3468%
Sunday3462%

Why it was late

Air traffic & airport (NAS) 56%Airline (crew, maintenance, ops) 29%Late inbound plane 11%Severe weather 5%

All flights DTW → PHL · Connecting off DL 1391? Check the risk

DL 1391: PHL → DTW

Scheduled to leave Philadelphia at 5:18 p.m. local time. Over the past year it arrived on time 66% of the time (239 flights), in line with other DL flights on the route at that hour (66%). Last seen in the data Aug 31, 2026.

Month by month

30%65%100%Jan 2026: 85% on time (27 flights)85JanFeb 2026: 79% on time (28 flights)79FebMar 2026: 84% on time (31 flights)84MarApr 2026: 70% on time (30 flights)70AprMay 2026: 65% on time (31 flights)65MayJun 2026: 53% on time (30 flights)53JunJul 2026: 42% on time (31 flights)42JulAug 2026: 55% on time (31 flights)55Aug

By day of week

DayFlightsOn time
Monday3554%
Tuesday3474%
Wednesday3474%
Thursday3465%
Friday3468%
Saturday3468%
Sunday3462%

Why it was late

Late inbound plane 45%Airline (crew, maintenance, ops) 27%Air traffic & airport (NAS) 15%Severe weather 13%

All flights PHL → DTW · Connecting off DL 1391? Check the risk

Questions

How often is DL 1391 from DTW to PHL late?

Delta Air Lines 1391 from Detroit, MI to Philadelphia, PA arrived 15 or more minutes late, was diverted or was cancelled on 33% of 239 scheduled flights between September 2025 and August 2026. 2.1% were cancelled.

How often is DL 1391 from PHL to DTW late?

Delta Air Lines 1391 from Philadelphia, PA to Detroit, MI arrived 15 or more minutes late, was diverted or was cancelled on 34% of 239 scheduled flights between September 2025 and August 2026. 2.1% were cancelled.

Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Delta Air Lines for today's flight. Method.