Washington (IAD) to Portland (PWM): On-Time Performance
Data through July 2026
Washington (IAD) to Portland (PWM) effectively runs on two schedules. In April 2025, 96% of arrivals were on time; in December 2025 that fell to 72% — a 24-point seasonal swing. Across the full period the route averages 86% on-time against a national 78%. Morning departures also hold up better than evening ones (93% vs 80%), which matters most in the rough months.
- On-time
- 86%
- arrived <15 min late
- Avg delay
- 12 min
- completed flights
- Cancelled
- 2.0%
- Flights/day
- 2.2
- last 12 months
- Duration
- 1h 47m
- scheduled
- Distance
- 493 mi
Best airline from IAD to PWM
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airwaysmost reliable | 87% | 12 min | 2.2% | 1,530 |
| United Airlines | 79% | 14 min | 0.7% | 141 |
Monthly on-time trend
Best time to fly from IAD to PWM
Aim for departures around 8 a.m. (93% on-time); avoid 10 p.m. departures (79%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 85% | 9 min |
| Tuesdaybest | 89% | 6 min |
| Wednesday | 87% | 16 min |
| Thursday | 85% | 19 min |
| Friday | 86% | 14 min |
| Saturday | 89% | 8 min |
| Sunday | 85% | 12 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft35%
- Airline operations38%
- National airspace system16%
- Weather11%
Frequently asked questions
- How often are flights from IAD to PWM delayed?
- 14% of IAD–PWM flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 12 minutes.
- Which airline is most reliable from IAD to PWM?
- Republic Airways has the best on-time record on this route at 87%, based on 1,530 flights. 2 airlines flew IAD–PWM frequently enough to compare in this period.
- What is the best time of day to fly from IAD to PWM?
- Departures around 8 a.m. have the best record (93% on-time), while departures around 10 p.m. have the worst (79%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from IAD to PWM?
- The scheduled IAD–PWM flight time averages 1h 47m over 493 miles. Actual arrival times vary — flights on this route land 15+ minutes late 14% of the time.
- How often are IAD to PWM flights cancelled?
- 2% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, slightly above the national rate of 1.6%.
- What is the worst month to fly from IAD to PWM?
- December 2025 was the roughest month in this dataset, with only 72% of arrivals on time. The best was April 2025 at 96%. If your dates are flexible, that 24-point gap is worth planning around.
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Based on 1,671 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.