ON TIMEBOARD

PWM → PHL on time

Portland Jetport (Portland, ME) to Philadelphia (Philadelphia, PA). Every scheduled flight, September 2025 to August 2026.

On time
78%
arrived < 15 min late
Cancelled
3.3%
1,322 flights
Typical arrival
−12 min
median vs schedule
When late
+104 min
average delay
Flights / day
4
1 airline

78% of flights from Portland to Philadelphia arrived on time over the past 12 months. That is about the typical U.S. route. The 10 a.m. departures ran on time 87% of the time; the 6 p.m. ones 67%. 11% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for PWM → PHL: when a flight was late, it was under 45 minutes late 51% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 43 three hours or more; 3.3% were cancelled outright.

Share of all 1,322 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
American Airlines1,32278%3.3%−12 min7.5%+104 minPiedmont Airlines 50%, American Airlines 37%, PSA Airlines 13%, Republic Airways 0%

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at PWM). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%5 a.m. departures: too few flights (44 flights)5a6 a.m. departures: 87% on time (187 flights)876a7 a.m. departures: 79% on time (136 flights)797a8 a.m. departures: too few flights (75 flights)8a9 a.m. departures: too few flights9a10 a.m. departures: 87% on time (119 flights)8710a11 a.m. departures: too few flights (34 flights)11anoon departures: 74% on time (167 flights)7412p1 p.m. departures: too few flights (29 flights)1p2 p.m. departures: too few flights (43 flights)2p3 p.m. departures: 76% on time (209 flights)763p4 p.m. departures: too few flights (24 flights)4p5 p.m. departures: too few flights (1 flights)5p6 p.m. departures: 67% on time (209 flights)676p7 p.m. departures: too few flights (45 flights)7p
PWM → PHL, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On PWM → PHL, each airline's last flight of the day was cancelled 5.2% of the time, against 2.6% for its earlier flights (2.0× as often). It arrived 3+ hours late 1.1% of the time (earlier flights: 2.8%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
American Airlines6:54 p.m.5.2%1.1%2.6%first flight 7:58 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in PHL tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: November (89%). Worst: August (70%).

40%70%100%Jan: 72% on time (256 flights)72JanFeb: 75% on time (243 flights)75FebMar: 81% on time (273 flights)81MarApr: 85% on time (289 flights)85AprMay: 83% on time (327 flights)83MayJun: 70% on time (372 flights)70JunJul: 71% on time (386 flights)71JulAug: 70% on time (394 flights)70AugSep: 80% on time (308 flights)80SepOct: 79% on time (327 flights)79OctNov: 89% on time (291 flights)89NovDec: 79% on time (263 flights)79Dec

By day of week

DayFlightsOn timeCancelled
Monday20272%5.0%
Tuesday19182%3.1%
Wednesday17187%1.2%
Thursday19174%4.7%
Friday19181%2.1%
Saturday17980%1.7%
Sunday19772%5.1%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Airline (crew, maintenance, ops) 44%Late inbound plane 39%Air traffic & airport (NAS) 15%Severe weather 2%

Cancellations: weather 36 · air traffic/airport 5 · airline 3

Month by month

50%75%100%Sep 2023Jan 2024Jan 2025Jan 2026May 2024: 87% on time, 3.0% cancelledJun 2024: 70% on time, 3.0% cancelledJul 2024: 68% on time, 2.1% cancelledAug 2024: 61% on time, 5.5% cancelledSep 2024: 82% on time, 0.0% cancelledOct 2024: 85% on time, 0.8% cancelledJun 2025: 69% on time, 2.5% cancelledJul 2025: 67% on time, 3.9% cancelledAug 2025: 78% on time, 0.8% cancelledSep 2025: 84% on time, 0.0% cancelledOct 2025: 69% on time, 0.9% cancelledNov 2025: 85% on time, 0.0% cancelledApr 2026: 93% on time, 0.0% cancelledMay 2026: 91% on time, 1.5% cancelledJun 2026: 73% on time, 2.5% cancelledJul 2026: 78% on time, 6.8% cancelledAug 2026: 72% on time, 4.8% cancelled
Share of flights on time, by month (hover a point for cancellations)
PWM → PHL, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
AA 29516:00 a.m.14687%2.7%−12 minAmerican Airlines

Worst days in the past year

DateFlightsOn timeCancelled
Dec 14, 202540%1
Aug 3, 202640%1
Dec 29, 202530%1
Mar 12, 202630%1
Jan 25, 202630%3

Questions

How often are flights from PWM to PHL on time?

78% of 1,322 scheduled flights from Portland, ME to Philadelphia, PA arrived within 15 minutes of schedule between September 2025 and August 2026. 3.3% were cancelled.

What is the best time of day to fly PWM to PHL?

Flights scheduled to leave at 10 a.m. were the most reliable (87% on time). The 6 p.m. departures were the least (67%).

What month has the most delays from PWM to PHL?

August (70% on time). The best month is November (89%), over 2023–2026.

Is the last flight of the day from PWM to PHL more likely to be cancelled?

Yes. Each airline's last PWM–PHL flight of the day was cancelled 5.2% of the time over the past year, against 2.6% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.