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Airport Reliability

SEA · Seattle

Seattle–Tacoma International Airport

80%
Departures within 15 minutes
10 min
Average departure delay
80%
Arrivals within 15 minutes
1.0%
Departures cancelled

Based on 184,285 departures and 184,297 arrivals. Data through May 2026.

What the data says

Morning-you made the right choice.

Departures from SEA departing between 3–6 AM arrived on time 94% of the time, versus 77% between 3–6 PM.

Tuesday has been the better bet.

A small edge: 83% on time on Tuesdays against 77% on Fridays.

When SEA gets messy

On-time by departure window
  • 12–3 AM79%(879 flights)
  • 3–6 AM94%(2519 flights)
  • 6–9 AM88%(32968 flights)
  • 9 AM–12 PM78%(40108 flights)
  • 12–3 PM79%(25759 flights)
  • 3–6 PM77%(31873 flights)
  • 6–9 PM77%(23433 flights)
  • 9 PM–12 AM79%(24263 flights)
On-time by weekday
  • Mon80%(26983 flights)
  • Tue83%(25293 flights)
  • Wed83%(25295 flights)
  • Thu78%(26634 flights)
  • Fri77%(26544 flights)
  • Sat81%(24004 flights)
  • Sun78%(27049 flights)
On-time trend by month
83%
May

Jun 72% → May 83% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202572%17216
July 202571%17933
August 202575%17578
September 202584%16054
October 202584%15259
November 202583%13767
December 202575%14352
January 202683%12952
February 202686%12132
March 202682%13963
April 202687%14353
May 202683%16243

Airlines departing SEA

Busiest routes from SEA

Based on 184,285 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.