Delta Air Lines ONT to SEA on-time performance
Delta Air Lines nonstop flights from Ontario to Seattle · Aug 2025 – Jul 2026
On-time arrivals
93%
arrived < 15 min late
Cancelled
0.0%
0 flights
Avg arrival delay
3 min
43 min when late
Rank on route
#1 of 4
route average 86% on time
Key facts
- Delta Air Lines flights on ONT to SEA arrived on time 93% of the time in Aug 2025 – Jul 2026.
- 0% were cancelled, and 3% arrived an hour or more late.
- That ranks #1 of 4 airlines on this route, which averaged 86% on time overall.
- The largest source of delay minutes was late-arriving aircraft (53%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft53%
- Air traffic control & airport congestion34%
- Airline (crew, maintenance, cleaning, fueling)13%
- Extreme weather0%
- Security0%
Other airlines on ONT to SEA
- Alaska Airlines82% on time · 10 min avg delay
- SkyWest Airlines92% on time · 8 min avg delay
- Frontier Airlines82% on time · 17 min avg delay
Full ONT to SEA comparison →
Delta Air Lines on-time record across all routes →
29 Delta Air Lines flights tracked on this route; 0 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.