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DelayAtlas

Carrier route record

ASKOASEA

Alaska Airlines · Kailua-Kona to Seattle

Flights
1,057
Period
July 2025 to June 2026
Share of route
74%
Carriers
2
AGRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.

Alaska on KOA to SEA earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,057 flights, with a median arrival 9 minutes early.

Set against the rest of the country, Alaska's KOA to SEA record is 8 points better than the US average of 77.6%. That gap is worth roughly 81 fewer late arrivals for every thousand flights.

Key figures

On time

85.7%

Arrivals under 15 minutes late, of 1,036 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.99%

National rate is 1.81%

Whole route

87.2%

Every carrier on KOA to SEA, 1,422 flights

These figures cover 1,057 flights between July 2025 and June 2026. The median arrival is 9 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.

Carrier by carrier

Alaska against every carrier on KOA to SEA

Alaska flew 1,057 of the 1,422 flights on KOA to SEA, most of the route. Its 85.7% on time is 2 points worse than the route as a whole, which runs 87.2%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 91.5% to Alaska at 85.7%.

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.

On-time performance by carrier on KOA to SEA
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines36591.5%46 min2.74%A
Alaska Airlines (this page)1,05785.7%60 min1.99%A

Departure window

When Alaska runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,057 flights.

  • 5am–8am10 flights
  • 8am–11am412 flights89.2%
  • 11am–2pm275 flights81.0%
  • 2pm–5pm1 flights
  • 5pm–8pm
  • 8pm–5am359 flights85.9%

Scale runs 75% to 95%. 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 81.0% on time against 89.2% for 8am–11am. 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 8am–11am window is the busiest, with 412 flights scheduled in it.

Across the year

Alaska on KOA to SEA through the year

On-time rate by calendar month84J84F86M93A84M91J87J89A84S79O88N81D
Darker means more delays. Figures are on-time percentages.April best, October worst

April is the best month on the calendar at 92.6% 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, Wednesday is the strongest day at 89.7% on time and Monday the weakest at 81.1%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week81.1Mon87.6Tue89.7Wed86.6Thu87.2Fri84.6Sat83.4Sun
Monday: 81.1 percent on time. Tuesday: 87.6 percent on time. Wednesday: 89.7 percent on time. Thursday: 86.6 percent on time. Friday: 87.2 percent on time. Saturday: 84.6 percent on time. Sunday: 83.4 percent on time

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 8,920 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    43%
  • National Airspace System
    29%
  • Carrier
    25%
  • Extreme weather
    3%
  • Security
    0%

43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 8,920 reported delay minutes here, that single category outweighs weather by 13 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 8,920 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.2% on time here.

Cancellations sit at 1.99% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 3.8% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

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 70.9% on time across 1,056 flights, 15 points below 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 15 points of difference.

One caution: this is a thin sample. 1,057 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 KOA to SEA

Put together: treat all of this as provisional. 1,057 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 85.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,036 completed flights over 12 months sit behind that.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.