Delta Air Lines SEA to ONT on-time performance
Delta Air Lines nonstop flights from Seattle to Ontario · Aug 2025 – Jul 2026
On-time arrivals
93%
arrived < 15 min late
Cancelled
0.0%
0 flights
Avg arrival delay
3 min
32 min when late
Rank on route
#1 of 4
route average 83% on time
Key facts
- Delta Air Lines flights on SEA to ONT arrived on time 93% of the time in Aug 2025 – Jul 2026.
- 0% were cancelled, and 0% arrived an hour or more late.
- That ranks #1 of 4 airlines on this route, which averaged 83% on time overall.
- The largest source of delay minutes was late-arriving aircraft (69%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft69%
- Airline (crew, maintenance, cleaning, fueling)31%
- Air traffic control & airport congestion0%
- Extreme weather0%
- Security0%
Other airlines on SEA to ONT
- Alaska Airlines77% on time · 12 min avg delay
- SkyWest Airlines89% on time · 7 min avg delay
- Frontier Airlines84% on time · 12 min avg delay
Full SEA to ONT 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.