Alaska Airlines ONT to SEA on-time performance
Alaska Airlines nonstop flights from Ontario to Seattle · Aug 2025 – Jul 2026
On-time arrivals
82%
arrived < 15 min late
Cancelled
1.8%
23 flights
Avg arrival delay
10 min
52 min when late
Rank on route
#3 of 4
route average 86% on time
Key facts
- Alaska Airlines flights on ONT to SEA arrived on time 82% of the time in Aug 2025 – Jul 2026.
- 1.8% were cancelled, and 4% arrived an hour or more late.
- That ranks #3 of 4 airlines on this route, which averaged 86% on time overall.
- The largest source of delay minutes was late-arriving aircraft (51%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft51%
- Airline (crew, maintenance, cleaning, fueling)30%
- Air traffic control & airport congestion18%
- Extreme weather1%
- Security0%
Other airlines on ONT to SEA
- SkyWest Airlines92% on time · 8 min avg delay
- Frontier Airlines82% on time · 17 min avg delay
- Delta Air Lines93% on time · 3 min avg delay
Full ONT to SEA comparison →
Alaska Airlines on-time record across all routes →
1,259 Alaska Airlines flights tracked on this route; 23 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.