Flight number record
AS 66
Alaska Airlines · Juneau to Seattle
- Route
- JNU → SEA
- Departs
- 18:31
- Flights
- 357
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 66, check with Alaska Airlines.
AS 66 earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 357 flights, with a median arrival 10 minutes early.
Set against the rest of the country, AS 66's record is 7 points better than the US average of 77.3%. That gap is worth roughly 70 fewer late arrivals for every thousand flights.
Key figures
On time
84.3%
Arrivals under 15 minutes late, of 351 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
1.68%
National rate is 1.89%
1 hour+ late
5.1%
National rate is 8.3%
These figures cover 357 flights between September 2025 and August 2026. The median arrival is 10 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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Schedule
When AS 66 flies
AS 66 flies JNU to SEA without a single fixed slot. Its most common scheduled departure was 18:31, used on 69 of 357 flights, with 18:47 (39 flights) and 18:58 (36 flights) next.
- Departs 18:3169 flights19.3%
- Departs 18:4739 flights10.9%
- Departs 18:5836 flights10.1%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 18:31 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and AS 66 runs 16 points better at 84.3%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
AS 66 next to JNU to SEA
Every carrier on JNU to SEA combined arrived on time 81.4% of the time across 1,589 flights, so AS 66 is 3 points ahead of it. Alaska flew 1,448 flights on the same city pair under all its flight numbers, including this one, and those ran 80.4% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 66thin sample | 357 | 84.3% | 64 min | 1.68% | B |
| All Alaska Airlines on JNU–SEA | 1,448 | 80.4% | 58 min | 1.86% | B |
| All carriers on JNU–SEA | 1,589 | 81.4% | 61 min | 1.83% | B |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 66 quarter by quarter
AS 66 did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.9% on time and its weakest Jul–Sep 2025 at 70.0%, a swing of 19 points on roughly 71 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights70.0%
- Oct–Dec 202588 flights84.5%
- Jan–Mar 202687 flights85.9%
- Apr–Jun 202690 flights88.9%
- Jul–Sep 202662 flights82.3%
Scale runs 60% to 95%.
By weekday, AS 66 did best on Monday at 92.5% on time and worst on Tuesday at 78.0%. Each day rests on about 51 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 66 runs when it is late
AS 66 often beats the schedule: 143 of 351 completed flights, 41%, arrived 15 minutes or more early. The 55 late arrivals split 21 under half an hour, 16 between 30 and 60 minutes, and 18 an hour or more.
- 15+ min early143 flights40.7%
- Within 15 min153 flights43.6%
- 15–29 min late21 flights6.0%
- 30–59 min late16 flights4.6%
- 1–2 hours late13 flights3.7%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 351 completed flights by arrival against schedule.
5 of 39 late departures made up the time and arrived on time, 13% of them. In the other direction, 21 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 SEA.
The worst days
Worst days for AS 66
The latest arrival of the period was on 11 September 2025, 5 hours 15 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 September 2025 | 5 hours 15 minutes | Carrier |
| 1 May 2026 | 4 hours 43 minutes | Carrier |
| 12 October 2025 | 4 hours 41 minutes | Late-arriving aircraft |
| 23 October 2025 | 3 hours 57 minutes | Late-arriving aircraft |
| 19 January 2026 | 3 hours 2 minutes | Late-arriving aircraft |
Delay causes
Why AS 66 runs late
Late-arriving aircraft accounts for 53% of the 3,513 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Late-arriving aircraft
- 31%Carrier
- 16%National Airspace System
- 0%Extreme weather
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,513 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 3,513 delay minutes reported on AS 66.
Cancellations sit at 1.68% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
5.1% 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 an hour, which a normal layover absorbs.
The 909 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 357 flights under AS 66 in the data flew JNU to SEA. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 357 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 AS 66
For a booking, read AS 66 as 84.3% on time with 1.68% cancelled over 357 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- JNU to SEA, every carrier and departure
- SEA to JNU, the return direction
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Alaska Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.