Carrier route record
ASSEA→JNU
Alaska Airlines · Seattle to Juneau
- Flights
- 1,447
- Period
- September 2025 to August 2026
- Share of route
- 91%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to JNU lands a B, about a point better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That rests on 1,447 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.3%, 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
78.7%
Arrivals under 15 minutes late, of 1,422 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
1.24%
National rate is 1.89%
Whole route
79.2%
Every carrier on SEA to JNU, 1,588 flights
These figures cover 1,447 flights between September 2025 and August 2026. The median arrival is 5 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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Carrier by carrier
Alaska against every carrier on SEA to JNU
Alaska flew 1,447 of the 1,588 flights on SEA to JNU, most of the route. Its 78.7% on time is about level with the route as a whole at 79.2%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 84.9% to Alaska at 78.7%. 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 | 84.9% | 42 min | 1.42% | B |
| Alaska Airlines (this page) | 1,447 | 78.7% | 51 min | 1.24% | B |
Flight by flight
Alaska flight numbers on SEA to JNU
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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 12 points, against half a point between the best and worst carrier.
- 5am–8am362 flights87.1%
- 8am–11am144 flights76.8%
- 11am–2pm455 flights76.9%
- 2pm–5pm—
- 5pm–8pm9 flights—
- 8pm–5am477 flights74.8%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.1% of the time, against 74.8% for the overnight window. That is 12 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 477 flights scheduled in it.
Across the year
Alaska on SEA to JNU through the year
December is the weak month at 65.1% on time, against 92.0% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 185 flights.
Across the week, Wednesday is the strongest day at 83.5% on time and Thursday the weakest at 71.8%, a spread of 12 points.
Arrival by arrival
How late Alaska on SEA to JNU runs when it is late
Alaska on SEA to JNU often beats the schedule: 429 of 1,422 completed flights, 30%, arrived 15 minutes or more early. The 303 late arrivals split 124 under half an hour, 105 between 30 and 60 minutes, and 74 an hour or more.
- 15+ min early429 flights30.2%
- Within 15 min690 flights48.5%
- 15–29 min late124 flights8.7%
- 30–59 min late105 flights7.4%
- 1–2 hours late46 flights3.2%
- 2+ hours late28 flights2.0%
Scale runs 0% to 100%.
Share of 1,422 completed flights by arrival against schedule.
84 of 345 late departures made up the time and arrived on time, 24% of them. 42 flights left on time and still arrived late.
The worst days
Worst days for Alaska on SEA to JNU
The latest arrival of the period was on 18 June 2026, 7 hours 37 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 June 2026 | 7 hours 37 minutes | Late-arriving aircraft |
| 26 September 2025 | 6 hours 7 minutes | Carrier |
| 11 December 2025 | 3 hours 57 minutes | Carrier |
| 25 November 2025 | 3 hours 52 minutes | Extreme weather |
| 5 January 2026 | 3 hours 22 minutes | Carrier |
Delay causes
Why Alaska runs late on this route
Carrier accounts for 52% of the 16,000 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Carrier
- 30%Late-arriving aircraft
- 11%National Airspace System
- 7%Extreme weather
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 8,141 of the 16,000 delay minutes reported here. The split is drawn from 15,536 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 87.1% on time here.
Cancellations sit at 1.24% against a national 1.89%, which is ordinary. Diversions add another 0.48%.
Connections and stage length
What a delay here costs
5.2% 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 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.
The return leg runs 80.4% on time across 1,448 flights, within 2 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 1,447 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 December 65.1%, a swing of 27 points. If the dates move at all, move them out of December before you think about anything else. 1,422 completed flights over 12 months sit behind that.
Related
Where to go next
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.