Best Time to Fly PDX to SEA: On-Time Stats by Hour & Airline
Portland International → Seattle/Tacoma International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 85.4% of Portland (PDX) to Seattle (SEA) flights arrived on time (4,942 scheduled flights). That is 7.7 points above the national average of 77.6%.
Among 3 airlines, Delta Air Lines led with 87.9% on time and Alaska Airlines was last with 82.6%.
Over 24 months, Tuesday was the most reliable day (88% on time) and July the worst month (79%).
The cancellation rate was 0.7% (US average 1.8%).
PDX to SEA on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Lines | 87.9% | 62 min | 0.0% | 281 |
| SkyWest Airlines | 86.1% | 59 min | 0.6% | 3,504 |
| Alaska Airlines | 82.6% | 42 min | 1.2% | 1,157 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PDX to SEA
On-time arrival % by scheduled departure hour (local time), 9,904 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 95.0% | 0.2% | 946 |
| 6am–7am | 92.3% | 0.3% | 577 |
| 7am–8am | 89.0% | 0.4% | 1,062 |
| 8am–9am | 89.1% | 0.8% | 234 |
| 9am–10am | 76.7% | 0.7% | 860 |
| 10am–11am | 84.6% | 0.3% | 718 |
| 11am–12pm | 86.6% | 0.9% | 693 |
| 12pm–1pm | 82.5% | 0.5% | 190 |
| 1pm–2pm | 81.5% | 0.9% | 969 |
| 2pm–3pm | 86.3% | 0.4% | 499 |
| 3pm–4pm | 85.4% | 0.1% | 895 |
| 4pm–5pm | 69.8% | 0.0% | 116 |
| 5pm–6pm | 85.7% | 0.4% | 999 |
| 6pm–7pm | Limited data | 21 | |
| 7pm–8pm | 77.2% | 1.4% | 662 |
| 8pm–9pm | 76.4% | 0.0% | 250 |
| 9pm–10pm | 75.6% | 0.8% | 128 |
| 10pm–11pm | 89.2% | 2.4% | 85 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PDX to SEA
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 86.8% | +0.5 pts | 0.0% | 190 |
| Christmas & New Year (Dec 20 - Jan 3) | 84.8% | -1.5 pts | 0.6% | 350 |
| Summer peak (Jun 15 - Aug 15) | 79.1% | -7.2 pts | 0.2% | 1,716 |
| All other days | 86.3% | — | 0.6% | 7,648 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).