Carrier route record
ASSEA→JNU
Alaska Airlines · Seattle to Juneau
- Flights
- 1,448
- Period
- July 2025 to June 2026
- Share of route
- 91%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to JNU lands a B, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,448 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to JNU from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.3%
Arrivals under 15 minutes late, of 1,420 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
1.45%
National rate is 1.81%
Whole route
76.6%
Every carrier on SEA to JNU, 1,589 flights
These figures cover 1,448 flights between July 2025 and June 2026. The median arrival is 3 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 SEA to JNU
Alaska flew 1,448 of the 1,589 flights on SEA to JNU, most of the route. Its 76.3% on time is about level with the route as a whole at 76.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 80.0% to Alaska at 76.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 Linesthin sample | 141 | 80.0% | 43 min | 0.71% | B+ |
| Alaska Airlines (this page) | 1,448 | 76.3% | 48 min | 1.45% | B |
Flight by flight
Alaska flight numbers on SEA to JNU
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 40 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am362 flights83.2%
- 8am–11am144 flights78.2%
- 11am–2pm455 flights76.9%
- 2pm–5pm—
- 5pm–8pm59 flights43.1%
- 8pm–5am428 flights73.6%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 43.1% on time, against 83.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 455 flights scheduled in it.
Across the year
Alaska on SEA to JNU through the year
July is the worst month at 58.2% on time, 34 points below April, the best at 92.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 186 flights.
Across the week, Tuesday is the strongest day at 80.7% on time and Thursday the weakest at 68.7%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Alaska runs late on this route
One category carries most of the weight here. Carrier accounts for 45% of the 16,000 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.
- 45%Carrier
- 34%Late-arriving aircraft
- 16%National Airspace System
- 6%Extreme weather
- 0%Security
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 7,225 of the 16,000 delay minutes reported here. The split is drawn from 16,181 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 83.2% on time here.
Cancellations sit at 1.45% against a national 1.81%, which is ordinary. Diversions add another 0.48%.
Connections and stage length
What a delay here costs
5.1% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 79.1% on time across 1,450 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,448 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Alaska on SEA to JNU
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 92.0% on time and July 58.2%, a swing of 34 points. If the dates move at all, move them out of July before you think about anything else. 1,420 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to JNU, every carrier
- Alaska on JNU to SEA, the return leg
- Delta Air Lines on SEA to JNU80.0%
- 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 7.04 million flight records
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.