PHL to SEA flight delays & on-time performance
Nonstop flights from Philadelphia International Airport to Seattle–Tacoma International Airport · 2,379 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at PHL or SEA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Philadelphia (PHL) to Seattle (SEA) arrived on time 70% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 1.8% were cancelled, and 7% arrived an hour or more late.
- American Airlines was the most punctual airline here (72% on time); Alaska Airlines was the least (68%).
- Departures scheduled around 8am did best (81% on time); around 6pm did worst (64%).
- Tuesday was the most reliable day to fly (76% on time) and Monday the least (67%).
- The largest source of delay minutes was air traffic control & airport congestion (42%).
Which airline is most on time from PHL to SEA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| American Airlines | 72% | 2.2% | 15 min | 7.0% | 649 |
| Delta Air Lines | 69% | 0.0% | 26 min | 7.4% | 82 |
| Alaska Airlines | 68% | 1.7% | 17 min | 7.3% | 657 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am56%19 flights
- 7am73%325 flights
- 8am81%174 flights
- 9am94%33 flights
- 4pm75%71 flights
- 6pm64%532 flights
- 7pm68%234 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday67%1.5% cancelled
- Tuesday76%1.5% cancelled
- Wednesday70%2.1% cancelled
- Thursday69%2.0% cancelled
- Friday68%2.4% cancelled
- Saturday71%1.0% cancelled
- Sunday71%2.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion42%
- Airline (crew, maintenance, cleaning, fueling)26%
- Late-arriving aircraft24%
- Extreme weather7%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather68%
- Airline (crew, maintenance, cleaning, fueling)24%
- Air traffic control & airport congestion8%
- Security0%
PHL to SEA: common questions
- How often are PHL to SEA flights on time?
- 70% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Philadelphia to Seattle cancelled?
- 1.8% of scheduled flights were cancelled (25 of 1,388).
- How long are typical delays?
- Across all flights the average arrival delay was 17 min (early arrivals count as zero). Flights that were late arrived 52 min behind schedule on average, and 7.1% of flights were an hour or more late.
- How long is taxi time at PHL?
- Flights on this route spent 24 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to PHL — 82% on time
More flights from Philadelphia
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: PHL → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.