Route Reliability
Portland → Seattle
PDX–SEA · 129 miles · Portland International Airport to Seattle–Tacoma International Airport
- 84%
- Arrive within 15 minutes
- 2 min
- Average arrival delay
- 0.6%
- Cancelled
- 6,680
- Flights in the data
Data through May 2026.
Who flies it best
Ranked by on-time arrivals. Historical results, not predictions.
- 1.Delta Air Lines88%2,650 flights
- 2.Alaska Airlines81%4,030 flights
What the data says
Morning flights do better here.
PDX–SEA flights departing between 3–6 AM arrived on time 95% of the time, versus 77% between 6–9 PM.
Saturday comes out ahead.
A small edge: 87% on time on Saturdays against 80% on Thursdays.
Delta Air Lines runs this route best.
Delta Air Lines arrived on time 88% of the time on this route; Alaska Airlines managed 81%.
Best historical flights
Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.
Top flights by on-time rate
More flights on this route
The breakdown
- Mon84%(973 flights)
- Tue86%(967 flights)
- Wed85%(957 flights)
- Thu80%(957 flights)
- Fri81%(945 flights)
- Sat87%(866 flights)
- Sun84%(972 flights)
- 3–6 AM95%(467 flights)
- 6–9 AM88%(1201 flights)
- 9 AM–12 PM81%(1481 flights)
- 12–3 PM84%(1065 flights)
- 3–6 PM83%(1209 flights)
- 6–9 PM77%(852 flights)
- 9 PM–12 AM84%(362 flights)
Jun 76% → May 86% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 76% | 626 |
| July 2025 | 77% | 665 |
| August 2025 | 80% | 636 |
| September 2025 | 83% | 579 |
| October 2025 | 86% | 574 |
| November 2025 | 88% | 502 |
| December 2025 | 80% | 505 |
| January 2026 | 87% | 483 |
| February 2026 | 91% | 437 |
| March 2026 | 86% | 520 |
| April 2026 | 91% | 548 |
| May 2026 | 86% | 562 |
Keep nerding
Based on 6,680 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.