BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
PHL→SEA

Philadelphia, PA (PHL) to Seattle, WA (SEA) flight delay odds

68.1% of 1,327 official scheduled PHL-to-SEA flights arrived on time; 18.5% arrived at least 30 minutes late and 1.8% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALVariable
68.1%arrived on time
18.5%30+ min late
1.8%cancelled
1,327scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late7.7%all scheduled flights
120+ minutes late2.2%all scheduled flights
Diverted0.2%did not reach as scheduled
Average arrival+7.7 mincompleted flights

Which departure time was most reliable for PHL to SEA?

Among qualifying PHL-to-SEA departure window results, Early morning had the highest on-time rate: 74.7% of 494 flights. Evening was lowest at 62.5% across 760 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning49474.7%13.2%0.6%
Afternoon4072.5%20.0%5.0%
Evening76062.5%22.5%2.5%

Which weekday was most reliable for PHL to SEA?

Among qualifying PHL-to-SEA weekday results, Tuesday had the highest on-time rate: 77.6% of 192 flights. Friday was lowest at 62.8% across 191 flights.

DayFlightsOn time30+ minCancelled
Monday19264.1%21.9%1.6%
Tuesday19277.6%12.5%1.0%
Wednesday18568.1%16.2%2.7%
Thursday19165.4%23.6%2.1%
Friday19162.8%23.0%2.6%
Saturday18469.6%15.2%0.0%
Sunday19269.3%17.2%2.6%

Which airline was most reliable for PHL to SEA?

Among qualifying PHL-to-SEA airline results, Delta Air Lines had the highest on-time rate: 72.5% of 51 flights. Alaska Airlines was lowest at 64.5% across 656 flights.

AirlineFlightsOn time30+ minCancelled
Alaska Airlines65664.5%22.4%1.5%
American Airlines62071.6%14.4%2.3%
Delta Air Lines5172.5%19.6%0.0%

Which month was most reliable for PHL to SEA?

Among qualifying PHL-to-SEA month results, February 2026 had the highest on-time rate: 83.6% of 55 flights. December 2025 was lowest at 37.6% across 93 flights.

MonthFlightsOn time30+ minCancelled
July 202512354.5%31.7%3.3%
August 202513664.7%23.5%1.5%
September 202512280.3%12.3%0.0%
October 202512369.1%13.8%1.6%
November 20258778.2%9.2%0.0%
December 20259337.6%37.6%1.1%
January 20266867.6%17.6%7.4%
February 20265583.6%10.9%3.6%
March 20267545.3%30.7%2.7%
April 202611482.5%7.9%0.9%
May 202615777.7%12.7%0.6%
June 202617469.5%17.2%2.3%

What drove PHL to SEA delay minutes?

National airspace was the largest recorded PHL-to-SEA delay category, accounting for 41.4% of 20,603 BTS-attributed delay minutes during July 2025–June 2026.

Airline26.1%
Late aircraft28.3%
National airspace41.4%
Weather4.1%
Security0.1%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.