Best Time to Fly BOS to IAD: On-Time Stats by Hour & Airline
Logan International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 83.5% of Boston (BOS) to Washington (IAD) flights arrived on time (1,516 scheduled flights). That is 5.9 points above the national average of 77.6%.
United Airlines was the most punctual of the 2 airlines on the route at 83.7%, while Republic Airways trailed at 77.5%.
March has been the best month (88% on time) and Thursday the weakest day of the week (79%).
2.7% of flights were cancelled, versus 1.8% nationally.
BOS 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 | 83.7% | 76 min | 2.3% | 1,459 |
| Republic Airways | 77.5% | 166 min | 14.0% | 57 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly BOS to IAD
On-time arrival % by scheduled departure hour (local time), 3,067 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 96.6% | 1.5% | 715 |
| 9am–10am | 91.1% | 1.1% | 730 |
| 11am–12pm | Limited data | 3 | |
| 12pm–1pm | 91.0% | 0.9% | 112 |
| 1pm–2pm | 97.1% | 0.0% | 34 |
| 2pm–3pm | 72.4% | 2.1% | 728 |
| 6pm–7pm | Limited data | 27 | |
| 7pm–8pm | 71.3% | 1.7% | 718 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on BOS 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) | 81.5% | -3.5 pts | 0.0% | 54 |
| Christmas & New Year (Dec 20 - Jan 3) | 84.9% | -0.1 pts | 0.8% | 120 |
| Summer peak (Jun 15 - Aug 15) | 76.1% | -8.8 pts | 3.4% | 560 |
| All other days | 84.9% | — | 1.5% | 2,333 |
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).