Best Time to Fly IAD to PDX: On-Time Stats by Hour & Airline
Washington Dulles International → Portland International
Data through July 2026 · Last updated October 18, 2026
291 flights were scheduled from Washington (IAD) to Portland (PDX) in the last 12 months, and 75.8% of those that flew arrived on time, 1.8 points below the US average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Friday was the most reliable day (83% on time) and July the worst month (62%).
The cancellation rate was 0.7% (US average 1.8%).
IAD to PDX 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 |
|---|---|---|---|---|
| United Airlines | 75.8% | 77 min | 0.7% | 291 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to PDX
On-time arrival % by scheduled departure hour (local time), 582 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5pm–6pm | 78.1% | 0.4% | 523 |
| 6pm–7pm | 65.7% | 2.8% | 36 |
| 7pm–8pm | Limited data | 23 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAD to PDX
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) | Limited data | 14 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 63.3% | -17.0 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 65.8% | -14.4 pts | 0.8% | 124 |
| All other days | 80.3% | — | 0.5% | 414 |
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).