IAD to BOS flight delays & on-time performance
Nonstop flights from Washington Dulles International Airport to Boston Logan International Airport · 412 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at IAD or BOS right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Washington (IAD) to Boston (BOS) arrived on time 77% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 2.5% were cancelled, and 9% arrived an hour or more late.
- Departures scheduled around 8am did best (92% on time); around 3pm did worst (43%).
- Saturday was the most reliable day to fly (85% on time) and Monday the least (72%).
- The largest source of delay minutes was air traffic control & airport congestion (62%).
Which airline is most on time from IAD to BOS?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| United Airlines | 78% | 2.1% | 16 min | 8.7% | 1,457 |
| Republic AirwaysRegional airline operating flights for American Eagle, Delta Connection and United Express. | 73% | 14.0% | 17 min | 10.2% | 57 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 8am92%233 flights
- 9am91%111 flights
- 10am85%27 flights
- 12pm80%360 flights
- 3pm43%59 flights
- 5pm61%365 flights
- 10pm81%354 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday72%4.5% cancelled
- Tuesday75%3.3% cancelled
- Wednesday77%0.9% cancelled
- Thursday74%1.4% cancelled
- Friday82%0.4% cancelled
- Saturday85%1.9% cancelled
- Sunday77%5.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion62%
- Late-arriving aircraft17%
- Airline (crew, maintenance, cleaning, fueling)15%
- Extreme weather5%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather79%
- Air traffic control & airport congestion21%
- Airline (crew, maintenance, cleaning, fueling)0%
- Security0%
IAD to BOS: common questions
- How often are IAD to BOS flights on time?
- 77% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Washington to Boston cancelled?
- 2.5% of scheduled flights were cancelled (38 of 1,514).
- How long are typical delays?
- Across all flights the average arrival delay was 16 min (early arrivals count as zero). Flights that were late arrived 69 min behind schedule on average, and 8.7% of flights were an hour or more late.
- How long is taxi time at IAD?
- Flights on this route spent 24 min taxiing from the gate to takeoff on average.
Related routes
Return trip: BOS to IAD — 84% on time
More flights from Washington
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: IAD → BOS, nonstop flights by US airlines that report to the DOT. How we calculate this.