Best Time to Fly IAD to BOS: On-Time Stats by Hour & Airline
Washington Dulles International → Logan International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 77.4% of Washington (IAD) to Boston (BOS) flights arrived on time (1,514 scheduled flights). That is in line with the national average of 77.6%.
Among 2 airlines, United Airlines led with 77.6% on time and Republic Airways was last with 73.5%.
Over 24 months, Saturday was the most reliable day (83% on time) and September the worst month (67%).
The cancellation rate was 2.5% (US average 1.8%).
IAD to BOS 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 | 77.6% | 69 min | 2.1% | 1,457 |
| Republic Airways | 73.5% | 62 min | 14.0% | 57 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to BOS
On-time arrival % by scheduled departure hour (local time), 3,065 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | 90.9% | 0.5% | 577 |
| 9am–10am | 90.6% | 3.0% | 132 |
| 10am–11am | Limited data | 27 | |
| 12pm–1pm | 79.4% | 0.9% | 667 |
| 1pm–2pm | 88.9% | 0.0% | 63 |
| 3pm–4pm | 54.8% | 7.1% | 112 |
| 4pm–5pm | 60.0% | 0.0% | 35 |
| 5pm–6pm | 62.8% | 2.2% | 729 |
| 7pm–8pm | Limited data | 1 | |
| 10pm–11pm | 78.6% | 1.7% | 722 |
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 BOS
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) | 75.9% | -2.2 pts | 0.0% | 54 |
| Christmas & New Year (Dec 20 - Jan 3) | 83.2% | +5.1 pts | 0.8% | 120 |
| Summer peak (Jun 15 - Aug 15) | 71.8% | -6.4 pts | 3.0% | 559 |
| All other days | 78.1% | — | 1.4% | 2,332 |
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).