Carrier route record
ASSEA→KOA
Alaska Airlines · Seattle to Kailua-Kona
- Flights
- 1,045
- Period
- September 2025 to August 2026
- Share of route
- 74%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to KOA sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land about 50 minutes behind schedule. That rests on 1,045 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Alaska on SEA to KOA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
73.9%
Arrivals under 15 minutes late, of 1,020 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
1.15%
National rate is 1.89%
Whole route
74.5%
Every carrier on SEA to KOA, 1,410 flights
These figures cover 1,045 flights between September 2025 and August 2026. The median arrival is 5 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Alaska against every carrier on SEA to KOA
Alaska flew 1,045 of the 1,410 flights on SEA to KOA, most of the route. Its 73.9% on time is about level with the route as a whole at 74.5%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 76.1% to Alaska at 73.9%.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 365 | 76.1% | 47 min | 2.19% | B |
| Alaska Airlines (this page) | 1,045 | 73.9% | 51 min | 1.15% | C |
Flight by flight
Alaska flight numbers on SEA to KOA
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Departure window
When Alaska runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier.
- 5am–8am1 flights—
- 8am–11am266 flights72.1%
- 11am–2pm296 flights71.5%
- 2pm–5pm171 flights83.3%
- 5pm–8pm311 flights72.4%
- 8pm–5am—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 71.5% on time against 83.3% for 2pm–5pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5pm–8pm window is the busiest, with 311 flights scheduled in it.
Across the year
Alaska on SEA to KOA through the year
April is the best month on the calendar at 95.1% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. January was the busiest month here, with 93 flights.
Across the week, Monday is the strongest day at 78.7% on time and Friday the weakest at 67.1%, a spread of 12 points.
Arrival by arrival
How late Alaska on SEA to KOA runs when it is late
Alaska on SEA to KOA often beats the schedule: 316 of 1,020 completed flights, 31%, arrived 15 minutes or more early. The 266 late arrivals split 110 under half an hour, 90 between 30 and 60 minutes, and 66 an hour or more.
- 15+ min early316 flights31.0%
- Within 15 min438 flights42.9%
- 15–29 min late110 flights10.8%
- 30–59 min late90 flights8.8%
- 1–2 hours late48 flights4.7%
- 2+ hours late18 flights1.8%
Scale runs 0% to 100%.
Share of 1,020 completed flights by arrival against schedule.
A late pushback is often recovered here: of 270 departures that left 15 minutes late or more, 87 still arrived on time. In the other direction, 83 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at KOA.
The worst days
Worst days for Alaska on SEA to KOA
The latest arrival of the period was on 1 October 2025, 4 hours 48 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 1 October 2025 | 4 hours 48 minutes | Carrier |
| 13 March 2026 | 4 hours 46 minutes | Extreme weather |
| 13 March 2026 | 4 hours 16 minutes | Late-arriving aircraft |
| 23 July 2026 | 4 hours 16 minutes | Carrier |
| 20 March 2026 | 4 hours 13 minutes | Carrier |
Delay causes
Why Alaska runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 13,000 reported delay minutes.
- 38%Carrier
- 33%Late-arriving aircraft
- 27%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,074 of the 13,000 delay minutes reported here. The split is drawn from 13,496 reported delay minutes.
Cancellations sit at 1.15% against a national 1.89%, which is ordinary. Diversions add another 1.24%.
Connections and stage length
What a delay here costs
6.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
At 2,688 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 85.8% on time across 1,047 flights, 12 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 12 points of difference.
One caution: this is a thin sample. 1,045 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Alaska on SEA to KOA
Put together: treat all of this as provisional. 1,045 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,020 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to KOA, every carrier
- Alaska on KOA to SEA, the return leg
- Delta Air Lines on SEA to KOA76.1%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.