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Route on-time record

PHL to SEA: most on-time flights and the best time to fly

Philadelphia (Philadelphia International Airport) to Seattle (Seattle–Tacoma International Airport). 1,269 nonstop flights in Jun 2025 to May 2026, 68% arrived within 15 minutes and 1.7% were cancelled. The most reliable flight number was American 888 at 8:25 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

Find me the most reliable flights fromtoonreturning(optional)

PHL → SEA

Philadelphia to Seattle: 1,269 nonstop flights a year

On time (12 months)

68%

Cancelled

1.7%

avg delay 18 min

Best time to leave

Before 9 AM

75% on time vs 61% 6 to 9 PM

Most reliable airline

American

70% chance on time

Check PHL to SEA fares

Lowest nonstop fare seen in the next two months: $217 (Alaska 370 on 2026-11-25). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · American 888

    8:25 AM → 11:34 AM6h 09m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    81%

    chance on time

    On time (history)
    89%
    Cancelled
    0.0%
    Avg arrival delay
    4 min
    • Arrived on time 89% of the time (44 flights, Jun 2025 to May 2026).
    • Never cancelled in 44 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 75% on time; 6 to 9 PM: 61%).
    • Departs outside PHL's trouble window (2 PM to 8 PM, when 72% of its 95 ground stops and delay programs started).

    Limited track record · 44 flights

    Find American 888 fares Opens this date on Aviasales

  2. #2 · American 2534

    8:36 AM → 11:46 AM6h 10m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    77%

    chance on time

    On time (history)
    82%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 82% of the time (11 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 75% on time; 6 to 9 PM: 61%).
    • Departs outside PHL's trouble window (2 PM to 8 PM, when 72% of its 95 ground stops and delay programs started).

    Limited track record · 11 flights

    Find American 2534 fares Opens this date on Aviasales

  3. #3 · American 3259

    7:35 PM → 10:58 PM6h 23m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    74%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    1 min
    • Arrived on time 100% of the time (10 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (6 to 9 PM: 61% on time; Before 9 AM: 75%).
    • Departs inside PHL's trouble window: 72% of its 95 ground stops and delay programs started between 2 PM and 8 PM.

    Limited track record · 10 flights

    Find American 3259 fares Opens this date on Aviasales

  4. #4 · Delta 2092

    7:10 AM → 10:00 AM5h 50m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    71%

    chance on time

    On time (history)
    79%
    Cancelled
    0.0%
    Avg arrival delay
    11 min
    • Arrived on time 79% of the time (24 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 75% on time; 6 to 9 PM: 61%).
    • Departs outside PHL's trouble window (2 PM to 8 PM, when 72% of its 95 ground stops and delay programs started).

    Limited track record · 24 flights

    Find Delta 2092 fares Opens this date on Aviasales

  5. #5 · Alaska 1584

    7:00 AM → 9:59 AM5h 59m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    70%

    chance on time

    On time (history)
    84%
    Cancelled
    0.0%
    Avg arrival delay
    24 min
    • Arrived on time 84% of the time (19 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 75% on time; 6 to 9 PM: 61%).
    • Departs outside PHL's trouble window (2 PM to 8 PM, when 72% of its 95 ground stops and delay programs started).

    Limited track record · 19 flights

    Find Alaska 1584 fares Opens this date on Aviasales

  6. #6 · American 2763

    6:08 PM → 9:23 PM6h 15m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    67%

    chance on time

    On time (history)
    77%
    Cancelled
    0.0%
    Avg arrival delay
    11 min
    • Arrived on time 77% of the time (44 flights, Jun 2025 to May 2026).
    • Never cancelled in 44 scheduled flights.
    • Leaves in this route's least on-time window (6 to 9 PM: 61% on time; Before 9 AM: 75%).
    • Departs inside PHL's trouble window: 72% of its 95 ground stops and delay programs started between 2 PM and 8 PM.

    Limited track record · 44 flights

    Find American 2763 fares Opens this date on Aviasales

  7. #7 · American 2522

    6:17 PM → 9:35 PM6h 18m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    64%

    chance on time

    On time (history)
    70%
    Cancelled
    0.0%
    Avg arrival delay
    13 min
    • Arrived on time 70% of the time (10 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (6 to 9 PM: 61% on time; Before 9 AM: 75%).
    • Departs inside PHL's trouble window: 72% of its 95 ground stops and delay programs started between 2 PM and 8 PM.
    • Lands inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.

    Limited track record · 10 flights

    Find American 2522 fares Opens this date on Aviasales

  8. #8 · Alaska 370

    7:25 AM → 10:30 AM6h 05m nonstop

    Local times, typical schedule. Last flown 2026-05-12.

    63%

    chance on time

    On time (history)
    62%
    Cancelled
    0.0%
    Avg arrival delay
    18 min
    • Arrived on time 62% of the time (85 flights, Jun 2025 to May 2026).
    • Never cancelled in 85 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 75% on time; 6 to 9 PM: 61%).
    • Departs outside PHL's trouble window (2 PM to 8 PM, when 72% of its 95 ground stops and delay programs started).

    Moderate track record · 85 flights

    Find Alaska 370 fares Opens this date on Aviasales

  9. #9 · Alaska 442

    7:16 PM → 10:28 PM6h 12m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    62%

    chance on time

    On time (history)
    72%
    Cancelled
    5.3%
    Avg arrival delay
    14 min
    • Arrived on time 72% of the time (18 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (6 to 9 PM: 61% on time; Before 9 AM: 75%).
    • Departs inside PHL's trouble window: 72% of its 95 ground stops and delay programs started between 2 PM and 8 PM.

    Limited track record · 18 flights

    Find Alaska 442 fares Opens this date on Aviasales

  10. #10 · Alaska 443

    6:47 PM → 9:52 PM6h 05m nonstop

    Local times, typical schedule. Last flown 2026-05-12.

    56%

    chance on time

    On time (history)
    56%
    Cancelled
    1.5%
    Avg arrival delay
    25 min
    • Arrived on time 56% of the time (336 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (6 to 9 PM: 61% on time; Before 9 AM: 75%).
    • Departs inside PHL's trouble window: 72% of its 95 ground stops and delay programs started between 2 PM and 8 PM.
    • Lands inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.

    Strong track record · 336 flights

    Find Alaska 443 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • American Airlines70%

    589 flights · 72% on time as flown · 2.0% cancel

  • Alaska Airlines63%

    656 flights · 63% on time as flown · 1.4% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM75%

    488 flights · avg delay 13 min

  • 6 to 9 PM61%

    729 flights · avg delay 22 min

Best day: Tuesday (77%). Worst: Friday (68%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
70
F
86
M
70
A
77
M
72
J
63
J
61
A
69
S
76
O
73
N
80
D
62

What delays this route

  • Air traffic control and airport volume38%
  • Late-arriving aircraft30%
  • Airline (crew, maintenance, boarding)28%
  • Severe weather4%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

Finding the most reliable connections from PHL to SEA…

PHL to SEA questions

What time of day is best to fly PHL to SEA?
Before 9 AM: 75% of flights arrived on time, against 61% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from PHL to SEA?
American, with a season-adjusted 70% chance of operating and arriving on time over 589 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on PHL to SEA?
July (61% on time); the best was February (86%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from PHL

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Live status: FAA delays and ground stops