Delta Air Lines SFO to BOS on-time performance
Delta Air Lines nonstop flights from San Francisco to Boston · Aug 2025 – Jul 2026
On-time arrivals
73%
arrived < 15 min late
Cancelled
1.5%
14 flights
Avg arrival delay
20 min
72 min when late
Rank on route
#4 of 5
route average 76% on time
Key facts
- Delta Air Lines flights on SFO to BOS arrived on time 73% of the time in Aug 2025 – Jul 2026.
- 1.5% were cancelled, and 9% arrived an hour or more late.
- That ranks #4 of 5 airlines on this route, which averaged 76% on time overall.
- The largest source of delay minutes was air traffic control & airport congestion (38%).
On-time trend by month
Why this airline's flights were late
- Air traffic control & airport congestion38%
- Late-arriving aircraft33%
- Airline (crew, maintenance, cleaning, fueling)24%
- Extreme weather6%
- Security0%
Other airlines on SFO to BOS
- United Airlines79% on time · 16 min avg delay
- JetBlue73% on time · 22 min avg delay
- Alaska Airlines78% on time · 15 min avg delay
- Southwest Airlines0% on time · 49 min avg delay
Full SFO to BOS comparison →
Delta Air Lines on-time record across all routes →
919 Delta Air Lines flights tracked on this route; 14 cancelled, 4 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.