ON TIMEBOARD

SEA → KOA on time

Seattle-Tacoma (Seattle, WA) to Ellison Onizuka Kona at Keāhole (Kona, HI). Every scheduled flight, September 2025 to August 2026.

On time
73%
arrived < 15 min late
Cancelled
1.4%
1,410 flights
Typical arrival
−5 min
median vs schedule
When late
+50 min
average delay
Flights / day
4
2 airlines

73% of flights from Seattle to Kona arrived on time over the past 12 months. That is worse than the typical U.S. route. The 2 p.m. departures ran on time 78% of the time; the noon ones 70%. Most reliable airline: Delta Air Lines (74%). 8% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for SEA → KOA: when a flight was late, it was under 45 minutes late 64% of the time. About 1 in 17 flights landed an hour or more late, and 1 in 128 three hours or more; 1.4% were cancelled outright.

Share of all 1,410 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines1,04572%1.1%−5 min6.3%+51 minAlaska Airlines
Delta Air Lines36574%2.2%−4 min4.7%+47 minDelta Air Lines

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at SEA). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%7 a.m. departures: too few flights (33 flights)7a8 a.m. departures: too few flights (30 flights)8a9 a.m. departures: too few flights (42 flights)9a10 a.m. departures: 70% on time (161 flights)7010a11 a.m. departures: too few flights (98 flights)11anoon departures: 70% on time (119 flights)7012p1 p.m. departures: too few flights (79 flights)1p2 p.m. departures: 78% on time (289 flights)782p3 p.m. departures: 72% on time (209 flights)723p4 p.m. departures: too few flights (38 flights)4p5 p.m. departures: too few flights (88 flights)5p6 p.m. departures: 72% on time (188 flights)726p7 p.m. departures: too few flights (35 flights)7p
SEA → KOA, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

By airline and hour

DepartsAlaska AirlinesDelta Air Lines
10 a.m.70%—
noon70%—
2 p.m.—77%
3 p.m.—68%
6 p.m.72%—

Last flight of the day

On SEA → KOA, each airline's last flight of the day was cancelled 1.9% of the time, against 0.7% for its earlier flights (2.6× as often). It arrived 3+ hours late 0.3% of the time (earlier flights: 1.0%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
Alaska Airlines6:59 p.m.1.9%0.3%0.7%first flight 11:27 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in KOA tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: April (86%). Worst: January (66%).

40%70%100%Jan: 66% on time (357 flights)66JanFeb: 74% on time (328 flights)74FebMar: 76% on time (368 flights)76MarApr: 86% on time (338 flights)86AprMay: 83% on time (347 flights)83MayJun: 74% on time (360 flights)74JunJul: 69% on time (370 flights)69JulAug: 70% on time (355 flights)70AugSep: 80% on time (351 flights)80SepOct: 80% on time (370 flights)80OctNov: 78% on time (334 flights)78NovDec: 69% on time (354 flights)69Dec

By day of week

DayFlightsOn timeCancelled
Monday20776%0.5%
Tuesday19876%0.0%
Wednesday19880%0.5%
Thursday20071%1.0%
Friday20265%2.0%
Saturday20266%3.0%
Sunday20375%3.0%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Airline (crew, maintenance, ops) 38%Air traffic & airport (NAS) 31%Late inbound plane 29%Severe weather 2%

Cancellations: weather 11 · airline 9

Month by month

30%65%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 86% on time, 0.0% cancelledOct 2023: 89% on time, 0.0% cancelledNov 2023: 77% on time, 0.0% cancelledDec 2023: 68% on time, 0.0% cancelledJan 2024: 38% on time, 22.9% cancelledFeb 2024: 78% on time, 1.0% cancelledMar 2024: 90% on time, 0.0% cancelledApr 2024: 78% on time, 0.9% cancelledMay 2024: 86% on time, 0.0% cancelledJun 2024: 79% on time, 0.0% cancelledJul 2024: 77% on time, 0.8% cancelledAug 2024: 77% on time, 0.0% cancelledSep 2024: 75% on time, 0.0% cancelledOct 2024: 83% on time, 0.0% cancelledDec 2024: 71% on time, 0.0% cancelledJan 2025: 87% on time, 1.6% cancelledFeb 2025: 81% on time, 0.0% cancelledMar 2025: 83% on time, 0.0% cancelledApr 2025: 86% on time, 0.0% cancelledMay 2025: 78% on time, 0.0% cancelledJun 2025: 60% on time, 1.7% cancelledJul 2025: 56% on time, 0.8% cancelledAug 2025: 67% on time, 1.7% cancelledSep 2025: 79% on time, 0.0% cancelledOct 2025: 68% on time, 3.3% cancelledNov 2025: 70% on time, 1.7% cancelledDec 2025: 68% on time, 3.3% cancelledJan 2026: 70% on time, 0.0% cancelledFeb 2026: 65% on time, 0.0% cancelledMar 2026: 56% on time, 2.4% cancelledApr 2026: 94% on time, 0.0% cancelledMay 2026: 85% on time, 0.0% cancelledJun 2026: 82% on time, 0.0% cancelledJul 2026: 73% on time, 1.6% cancelledAug 2026: 65% on time, 4.5% cancelled
Share of flights on time, by month (hover a point for cancellations)
SEA → KOA, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
AS 20411:27 a.m.22673%0.4%−6 minAlaska Airlines
DL 3402:30 p.m.36574%2.2%−4 minDelta Air Lines
AS 2383:59 p.m.25675%1.2%−7 minAlaska Airlines
AS 2006:59 p.m.23174%0.4%−6 minAlaska Airlines

Worst days in the past year

DateFlightsOn timeCancelled
Mar 20, 202640%0
Feb 8, 202640%0
Dec 20, 202540%0
Nov 6, 202540%0
Dec 15, 202540%0

Questions

How often are flights from SEA to KOA on time?

73% of 1,410 scheduled flights from Seattle, WA to Kona, HI arrived within 15 minutes of schedule between September 2025 and August 2026. 1.4% were cancelled.

What is the best time of day to fly SEA to KOA?

Flights scheduled to leave at 2 p.m. were the most reliable (78% on time). The noon departures were the least (70%).

Which airline is most on time from SEA to KOA?

Delta Air Lines: 74% of its 365 flights on the route arrived on time. Alaska Airlines: 72%.

What month has the most delays from SEA to KOA?

January (66% on time). The best month is April (86%), over 2023–2026.

Is the last flight of the day from SEA to KOA more likely to be cancelled?

Yes. Each airline's last SEA–KOA flight of the day was cancelled 1.9% of the time over the past year, against 0.7% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.