Carrier route record
AAPHL→SEA
American Airlines · Philadelphia to Seattle
- Flights
- 620
- Period
- July 2025 to June 2026
- Share of route
- 47%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on PHL to SEA sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 620 flights, with a median arrival 4 minutes early.
The national on-time rate over the same period is 77.6%, so American on PHL to SEA runs 4 points behind the country as a whole. Across a thousand flights that is about 42 extra late arrivals.
Key figures
On time
73.4%
Arrivals under 15 minutes late, of 605 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
2.26%
National rate is 1.81%
Whole route
69.5%
Every carrier on PHL to SEA, 1,327 flights
These figures cover 620 flights between July 2025 and June 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
American against every carrier on PHL to SEA
American flew 620 of the 1,327 flights on PHL to SEA, about 47% of it. Its 73.4% on time is 4 points better than the route as a whole, which runs 69.5%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from American at 73.4% to Alaska at 65.6%. One 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 |
|---|---|---|---|---|---|
| American Airlines (this page) | 620 | 73.4% | 49 min | 2.26% | C |
| Delta Air Linesthin sample | 51 | 72.5% | 52 min | 0.00% | C+ |
| Alaska Airlines | 656 | 65.6% | 54 min | 1.52% | C |
Departure window
When American runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 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–11am208 flights83.6%
- 11am–2pm—
- 2pm–5pm19 flights—
- 5pm–8pm393 flights67.8%
- 8pm–5am—
Scale runs 60% 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 67.8% for the evening window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 393 flights scheduled in it.
Across the year
American on PHL to SEA through the year
December is the weak month at 40.0% on time, against 88.9% in April. 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. June was the busiest month here, with 87 flights.
Across the week, Tuesday is the strongest day at 77.9% on time and Friday the weakest at 68.9%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why American runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,879 reported delay minutes.
- 37%National Airspace System
- 36%Carrier
- 21%Late-arriving aircraft
- 6%Extreme weather
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,911 minutes out of 7,879, against a national NAS share of 21%. The split is drawn from 7,879 reported delay minutes.
The largest share of delay minutes, 36%, 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 2,839 of the 7,879 delay minutes reported here.
Cancellations sit at 2.26% against a national 1.81%, which is ordinary. Diversions add another 0.16%.
Connections and stage length
What a delay here costs
5.8% 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 roughly 50 minutes, which a normal layover absorbs.
At 2,379 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 83.9% on time across 619 flights, 11 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 11 points of difference.
One caution: this is a thin sample. 620 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.
What to do with this
Booking American on PHL to SEA
Put together: treat all of this as provisional. 620 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 605 completed flights over 12 months sit behind that.
Related
Where to go next
- PHL to SEA, every carrier
- American on SEA to PHL, the return leg
- Alaska Airlines on PHL to SEA65.6%
- American Airlines network-wide record
- Philadelphia International (PHL) delay statistics
- Seattle-Tacoma International (SEA) 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.