Route reliability record
PHL→PWM
Philadelphia to Portland
- Flights
- 729
- Period
- July 2025 to June 2026
- Distance
- 364 mi
- Carriers
- 3
This route sits in the middle of the pack with a B−. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 729 PHL to PWM flights, with a median arrival 6 minutes early.
Best time to fly PHL to PWM: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 83.6% of the time and Tuesday flights 90.0%, against 75.8% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.8%
Arrivals under 15 minutes late, of 702 completed flights
Avg delay
90 min
Across delayed arrivals only, not all flights
Cancelled
3.43%
National rate is 1.81%
Best carrier
American
75.6% on time across 528 flights
These figures cover 729 flights between July 2025 and June 2026. Beyond the headline rate, 11.4% 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
Which airline is most reliable on PHL to PWM
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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 1 | 100.0% | — | 0.00% | A+ |
| PSA Airlinesthin sample | 200 | 76.1% | 110 min | 8.00% | B− |
| American Airlines | 528 | 75.6% | 83 min | 1.70% | B |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 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–11am178 flights83.6%
- 11am–2pm109 flights80.7%
- 2pm–5pm84 flights72.3%
- 5pm–8pm114 flights71.2%
- 8pm–5am244 flights71.1%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 83.6% of the time, against 71.1% for the overnight window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 244 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 25 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 66.4% on time, 25 points below April, the best at 91.4%. 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 119 flights.
Across the week, Tuesday is the strongest day at 90.0% on time and Thursday the weakest at 62.9%. 27 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 15,000 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.
- 50%Late-arriving aircraft
- 35%Carrier
- 11%National Airspace System
- 4%Extreme weather
50% 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 15,000 reported delay minutes here, that single category outweighs weather by 12 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 15,254 reported delay minutes.
The largest share of delay minutes, 35%, 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 5,295 of the 15,000 delay minutes reported here.
Cancellations run at 3.43%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.4% 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.
At 364 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 8am–11am window matters as much as it does.
The return leg runs 77.5% on time across 731 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.
One caution: this is a thin sample. 729 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.
Work out the risk of missing a connection in PWM after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.43% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 702 completed flights over 12 months sit behind that.
Common questions
PHL to PWM questions
How often is PHL to PWM delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.2% of the 729 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is PHL to PWM compared with the rest of the country?
75.8% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B− on this site's grading scale.
What time of day has the fewest delays on PHL to PWM?
The 8am–11am departure window is the strongest at 83.6% on time. The 8pm–5am window is the weakest at 71.1%, 13 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on PHL to PWM?
July is the weakest month at 66.4% on time, compared with 91.4% in April. Across the year that is 25 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- PWM to PHL — the return legseparate record
- Philadelphia International (PHL) delay statistics
- PSA Airlines on PHL to PWM76.1%
- American Airlines on PHL to PWM75.6%
- PHL to ATL, a related route79.2%
- ORD to PWM, a related route74.0%
- PHL to MCO, a related route72.4%
- Republic Airways on-time record100.0%
- PSA Airlines on-time record76.1%
- American Airlines on-time record75.6%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. PHL to PWM and PWM to PHL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.