Delta Air Lines SEA to MIA on-time performance
Delta Air Lines nonstop flights from Seattle to Miami · Aug 2025 – Jul 2026
On-time arrivals
79%
arrived < 15 min late
Cancelled
1.4%
5 flights
Avg arrival delay
14 min
60 min when late
Rank on route
#2 of 3
route average 78% on time
Key facts
- Delta Air Lines flights on SEA to MIA arrived on time 79% of the time in Aug 2025 – Jul 2026.
- 1.4% were cancelled, and 6% arrived an hour or more late.
- That ranks #2 of 3 airlines on this route, which averaged 78% on time overall.
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (56%).
On-time trend by month
Why this airline's flights were late
- Airline (crew, maintenance, cleaning, fueling)56%
- Air traffic control & airport congestion40%
- Extreme weather3%
- Late-arriving aircraft0%
- Security0%
Other airlines on SEA to MIA
- American Airlines77% on time · 18 min avg delay
- Alaska Airlines80% on time · 9 min avg delay
Full SEA to MIA comparison →
Delta Air Lines on-time record across all routes →
365 Delta Air Lines flights tracked on this route; 5 cancelled, 3 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.