ON TIMEBOARD

SEA → JNU on time

Seattle-Tacoma (Seattle, WA) to Juneau (Juneau, AK). Every scheduled flight, September 2025 to August 2026.

On time
78%
arrived < 15 min late
Cancelled
1.3%
1,588 flights
Typical arrival
−5 min
median vs schedule
When late
+51 min
average delay
Flights / day
4
2 airlines

78% of flights from Seattle to Juneau arrived on time over the past 12 months. That is about the typical U.S. route. The 7 a.m. departures ran on time 86% of the time; the 7 p.m. ones 62%. Most reliable airline: Delta Air Lines (84%). 7% 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 → JNU: when a flight was late, it was under 45 minutes late 64% of the time. About 1 in 20 flights landed an hour or more late, and 1 in 176 three hours or more; 1.3% were cancelled outright.

Share of all 1,588 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines1,44777%1.2%−5 min5.0%+51 minAlaska Airlines
Delta Air Lines14184%1.4%−2 min4.3%+42 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: 86% on time (362 flights)867a8 a.m. departures: too few flights8a9 a.m. departures: 75% on time (116 flights)759a10 a.m. departures: too few flights (28 flights)10a11 a.m. departures: 74% on time (334 flights)7411anoon departures: too few flights12p1 p.m. departures: 82% on time (121 flights)821p2 p.m. departures: too few flights2p3 p.m. departures: too few flights (20 flights)3p4 p.m. departures: 84% on time (121 flights)844p5 p.m. departures: too few flights5p6 p.m. departures: too few flights6p7 p.m. departures: 62% on time (126 flights)627p8 p.m. departures: 80% on time (107 flights)808p9 p.m. departures: 74% on time (158 flights)749p10 p.m. departures: too few flights (31 flights)10p11 p.m. departures: too few flights (64 flights)11p
SEA → JNU, 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
7 a.m.86%—
9 a.m.75%—
11 a.m.74%—
1 p.m.82%—
4 p.m.—84%
7 p.m.62%—
8 p.m.80%—
9 p.m.74%—

Last flight of the day

On SEA → JNU, each airline's last flight of the day was cancelled 2.8% of the time, against 0.7% for its earlier flights (3.7× as often). It arrived 3+ hours late 0.3% of the time (earlier flights: 0.7%). 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 Airlines9:23 p.m.2.8%0.3%0.7%first flight 7:08 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 JNU tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: September (83%). Worst: July (65%).

40%70%100%Jan: 69% on time (275 flights)69JanFeb: 80% on time (255 flights)80FebMar: 77% on time (279 flights)77MarApr: 80% on time (285 flights)80AprMay: 69% on time (398 flights)69MayJun: 69% on time (583 flights)69JunJul: 65% on time (650 flights)65JulAug: 71% on time (619 flights)71AugSep: 83% on time (508 flights)83SepOct: 82% on time (370 flights)82OctNov: 80% on time (270 flights)80NovDec: 75% on time (274 flights)75Dec

By day of week

DayFlightsOn timeCancelled
Monday23275%0.4%
Tuesday22683%1.8%
Wednesday22884%0.9%
Thursday22471%0.9%
Friday22781%1.3%
Saturday22576%1.3%
Sunday22676%2.2%

Why flights were late

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

Airline (crew, maintenance, ops) 52%Late inbound plane 30%Air traffic & airport (NAS) 11%Severe weather 7%

Cancellations: airline 10 · weather 10

Month by month

50%75%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 87% on time, 0.6% cancelledOct 2023: 88% on time, 0.8% cancelledApr 2024: 77% on time, 0.0% cancelledMay 2024: 61% on time, 1.4% cancelledJun 2024: 67% on time, 0.0% cancelledJul 2024: 57% on time, 0.9% cancelledAug 2024: 66% on time, 0.5% cancelledSep 2024: 76% on time, 1.2% cancelledOct 2024: 80% on time, 2.4% cancelledMay 2025: 66% on time, 0.8% cancelledJun 2025: 63% on time, 0.5% cancelledJul 2025: 59% on time, 1.8% cancelledAug 2025: 73% on time, 0.5% cancelledSep 2025: 86% on time, 1.7% cancelledOct 2025: 80% on time, 2.4% cancelledMay 2026: 81% on time, 0.0% cancelledJun 2026: 76% on time, 0.5% cancelledJul 2026: 80% on time, 0.0% cancelledAug 2026: 73% on time, 1.5% cancelled
Share of flights on time, by month (hover a point for cancellations)
SEA → JNU, 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 617:00 a.m.36286%0.3%−14 minAlaska Airlines
DL 21694:40 p.m.14184%1.4%−2 minDelta Air Lines
AS 719:23 p.m.26568%1.5%+1 minAlaska Airlines

Worst days in the past year

DateFlightsOn timeCancelled
Jan 18, 202630%2
Mar 19, 202630%0
Feb 1, 202630%0
Dec 28, 202530%1
Dec 30, 202530%2

Questions

How often are flights from SEA to JNU on time?

78% of 1,588 scheduled flights from Seattle, WA to Juneau, AK arrived within 15 minutes of schedule between September 2025 and August 2026. 1.3% were cancelled.

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

Flights scheduled to leave at 7 a.m. were the most reliable (86% on time). The 7 p.m. departures were the least (62%).

Which airline is most on time from SEA to JNU?

Delta Air Lines: 84% of its 141 flights on the route arrived on time. Alaska Airlines: 77%.

What month has the most delays from SEA to JNU?

July (65% on time). The best month is September (83%), over 2023–2026.

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

Yes. Each airline's last SEA–JNU flight of the day was cancelled 2.8% 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.