Carrier route record

ASSEA→AUS

Alaska Airlines · Seattle to Austin

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

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

Alaska on SEA to AUS lands a B+, about a point better than the national rate of 77.6%. About one flight in five 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 1,096 flights, with a median arrival 2 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to AUS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

78.4%

Arrivals under 15 minutes late, of 1,086 completed flights

Avg delay

48 min

Across delayed arrivals only, not all flights

Cancelled

0.73%

National rate is 1.81%

Whole route

79.1%

Every carrier on SEA to AUS, 2,059 flights

These figures cover 1,096 flights between July 2025 and June 2026. The median arrival is 2 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 AUS

Alaska flew 1,096 of the 2,059 flights on SEA to AUS, most of the route. Its 78.4% on time is about level with the route as a whole at 79.1%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 81.0% to Southwest at 40.7%. 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.

On-time performance by carrier on SEA to AUS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	936	81.0%	72 min	1.28%	B
Alaska Airlines (this page)	1,096	78.4%	48 min	0.73%	B+
Southwest Airlinesthin sample	27	40.7%	42 min	0.00%	F+

Flight by flight

Alaska flight numbers on SEA to AUS

Departure window

When Alaska runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,096 flights.

5am–8am—
8am–11am365 flights82.4%
11am–2pm353 flights80.3%
2pm–5pm—
5pm–8pm298 flights72.7%
8pm–5am80 flights72.5%

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 82.4% of the time, against 72.5% for the overnight window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 365 flights scheduled in it.

Across the year

Alaska on SEA to AUS through the year

Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 46.7% on time, 47 points below April, the best at 94.0%. 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 123 flights.

Across the week, Tuesday is the strongest day at 86.9% on time and Sunday the weakest at 73.6%. 13 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 11,000 reported delay minutes.

Carrier
34%
National Airspace System
32%
Late-arriving aircraft
31%
Extreme weather
3%
Security
0%

32% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,584 minutes out of 11,000, against a national NAS share of 21%. The split is drawn from 11,188 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 82.4% on time here.

Cancellations are rare at 0.73%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.1% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

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 82.0% on time across 1,096 flights, 4 points above 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 SEA to AUS

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 94.0% on time and July 46.7%, a swing of 47 points. If the dates move at all, move them out of July before you think about anything else. 1,086 completed flights over 12 months sit behind that.

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.

Key figures