Delta Air Lines SEA to BOS on-time performance
Delta Air Lines nonstop flights from Seattle to Boston · Aug 2025 – Jul 2026
On-time arrivals
80%
arrived < 15 min late
Cancelled
1.6%
17 flights
Avg arrival delay
15 min
69 min when late
Rank on route
#1 of 3
route average 75% on time
Key facts
- Delta Air Lines flights on SEA to BOS arrived on time 80% of the time in Aug 2025 – Jul 2026.
- 1.6% were cancelled, and 6% arrived an hour or more late.
- That ranks #1 of 3 airlines on this route, which averaged 75% on time overall.
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (38%).
On-time trend by month
Why this airline's flights were late
- Airline (crew, maintenance, cleaning, fueling)38%
- Air traffic control & airport congestion33%
- Late-arriving aircraft20%
- Extreme weather9%
- Security0%
Other airlines on SEA to BOS
- Alaska Airlines75% on time · 13 min avg delay
- JetBlue53% on time · 42 min avg delay
Full SEA to BOS comparison →
Delta Air Lines on-time record across all routes →
1,034 Delta Air Lines flights tracked on this route; 17 cancelled, 8 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.