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DelayAtlas

Carrier route record

ASAUSSEA

Alaska Airlines · Austin to Seattle

Flights
1,096
Period
July 2025 to June 2026
Share of route
53%
Carriers
3
BGRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.

Alaska on AUS to SEA lands a B, 4 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 1,096 flights, with a median arrival 6 minutes early.

Set against the rest of the country, Alaska's AUS to SEA record is 4 points better than the US average of 77.6%. That gap is worth roughly 44 fewer late arrivals for every thousand flights.

Key figures

On time

82.0%

Arrivals under 15 minutes late, of 1,083 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

1.00%

National rate is 1.81%

Whole route

82.8%

Every carrier on AUS to SEA, 2,058 flights

These figures cover 1,096 flights between July 2025 and June 2026. The median arrival is 6 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 AUS to SEA

Alaska flew 1,096 of the 2,058 flights on AUS to SEA, most of the route. Its 82.0% on time is about level with the route as a whole at 82.8%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 84.9% to Southwest at 42.3%. 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.

On-time performance by carrier on AUS to SEA
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines93584.9%94 min1.07%B
Alaska Airlines (this page)1,09682.0%55 min1.00%B
Southwest Airlinesthin sample2742.3%36 min3.70%F−

Flight by flight

Alaska flight numbers on AUS to SEA

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 15 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–8am280 flights84.1%
  • 8am–11am134 flights87.3%
  • 11am–2pm226 flights85.3%
  • 2pm–5pm139 flights87.5%
  • 5pm–8pm293 flights73.0%
  • 8pm–5am24 flights

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 2pm–5pm slot at 87.5% on time, ahead of 5pm–8pm at 73.0%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5pm–8pm window is the busiest, with 293 flights scheduled in it.

Across the year

Alaska on AUS to SEA through the year

On-time rate by calendar month83J93F72M92A90M81J76J79A84S85O85N70D
Darker means more delays. Figures are on-time percentages.February best, December worst

December is the weak month at 69.9% on time, against 92.5% in February. 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 123 flights.

Across the week, Wednesday is the strongest day at 85.4% on time and Sunday the weakest at 78.9%. 7 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.6Mon81.5Tue85.4Wed81.4Thu82.0Fri81.1Sat78.9Sun
Monday: 83.6 percent on time. Tuesday: 81.5 percent on time. Wednesday: 85.4 percent on time. Thursday: 81.4 percent on time. Friday: 82.0 percent on time. Saturday: 81.1 percent on time. Sunday: 78.9 percent on time

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 11,000 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.

  • Late-arriving aircraft
    43%
  • National Airspace System
    28%
  • Carrier
    21%
  • Extreme weather
    5%
  • Security
    3%

43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 11,000 reported delay minutes here, that single category outweighs weather by 9 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 10,669 reported delay minutes.

Cancellations sit at 1.00% against a national 1.81%, which is ordinary. Diversions add another 0.18%.

Connections and stage length

What a delay here costs

5.2% 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 about 55 minutes, which a normal layover absorbs.

At 1,770 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 78.4% on time across 1,096 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.

The sample behind these figures is 1,096 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 AUS to SEA

Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 92.5% on time and December 69.9%, a swing of 23 points. If the dates move at all, move them out of December before you think about anything else. 1,083 completed flights over 12 months sit behind that.

Related

Where to go next

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.