Best Time to Fly PWM to IAD: On-Time Stats by Hour & Airline
Portland International Jetport → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 86.5% of Portland (PWM) to Washington (IAD) flights arrived on time (686 scheduled flights). That is 8.9 points above the national average of 77.6%.
United Airlines was the most punctual of the 2 airlines on the route at 94.7%, while Republic Airways trailed at 85.5%.
March has been the best month (93% on time) and Monday the weakest day of the week (84%).
2.3% of flights were cancelled, versus 1.8% nationally.
PWM to IAD 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 | 94.7% | 69 min | 0.0% | 75 |
| Republic Airways | 85.5% | 84 min | 2.6% | 611 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PWM to IAD
On-time arrival % by scheduled departure hour (local time), 1,486 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 95.4% | 1.4% | 355 |
| 9am–10am | 93.2% | 1.7% | 179 |
| 10am–11am | 90.7% | 2.0% | 99 |
| 12pm–1pm | 92.7% | 0.0% | 41 |
| 2pm–3pm | 78.0% | 1.9% | 314 |
| 6pm–7pm | Limited data | 18 | |
| 7pm–8pm | 80.3% | 4.2% | 480 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PWM to IAD
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 | 19 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 93.3% | +4.8 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 80.9% | -7.6 pts | 5.9% | 474 |
| All other days | 88.5% | — | 1.0% | 963 |
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).