United Airlines IAD to BOS on-time performance
United Airlines nonstop flights from Washington to Boston · Aug 2025 – Jul 2026
On-time arrivals
78%
arrived < 15 min late
Cancelled
2.1%
30 flights
Avg arrival delay
16 min
69 min when late
Rank on route
#1 of 2
route average 77% on time
Key facts
- United Airlines flights on IAD to BOS arrived on time 78% of the time in Aug 2025 – Jul 2026.
- 2.1% were cancelled, and 9% arrived an hour or more late.
- That ranks #1 of 2 airlines on this route, which averaged 77% on time overall.
- The largest source of delay minutes was air traffic control & airport congestion (63%).
On-time trend by month
Why this airline's flights were late
- Air traffic control & airport congestion63%
- Late-arriving aircraft17%
- Airline (crew, maintenance, cleaning, fueling)15%
- Extreme weather5%
- Security0%
Other airlines on IAD to BOS
- Republic Airways73% on time · 17 min avg delay
Full IAD to BOS comparison →
United Airlines on-time record across all routes →
1,457 United Airlines flights tracked on this route; 30 cancelled, 0 diverted.
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. How we calculate this.