Carrier route record

ASSEA→AUS

Alaska Airlines · Seattle to Austin

Flights: 1,051
Period: September 2025 to August 2026
Share of route: 50%
Carriers: 3

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

Alaska on SEA to AUS lands a B+, 3 points 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 about 45 minutes on average. That rests on 1,051 flights, with a median arrival 3 minutes early.

The US average over the same twelve months is 77.3%, 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

80.1%

Arrivals under 15 minutes late, of 1,043 completed flights

Avg delay

44 min

Across delayed arrivals only, not all flights

Cancelled

0.67%

National rate is 1.89%

Whole route

78.5%

Every carrier on SEA to AUS, 2,090 flights

These figures cover 1,051 flights between September 2025 and August 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.

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Carrier by carrier

Alaska against every carrier on SEA to AUS

Alaska flew 1,051 of the 2,090 flights on SEA to AUS, most of the route. Its 80.1% on time is 2 points better than the route as a whole, which runs 78.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 80.1% to Southwest at 42.7%. 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	950	80.1%	67 min	1.05%	B
Alaska Airlines (this page)	1,051	80.1%	44 min	0.67%	B+
Southwest Airlinesthin sample	89	42.7%	57 min	0.00%	F+

Flight by flight

Alaska flight numbers on SEA to AUS

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

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 1,051 flights.

5am–8am—
8am–11am365 flights79.7%
11am–2pm354 flights81.6%
2pm–5pm—
5pm–8pm302 flights78.4%
8pm–5am30 flights83.3%

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is the strongest at 83.3% on time. The full set of windows spans 5 points.

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 58.1% on time, 36 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. May was the busiest month here, with 93 flights.

Across the week, Tuesday is the strongest day at 84.6% on time and Monday the weakest at 73.0%, a spread of 12 points.

Arrival by arrival

How late Alaska on SEA to AUS runs when it is late

Most of the lateness is short. 109 of the 208 late arrivals were under half an hour behind, and 34 reached an hour or more.

15+ min early231 flights22.1%
Within 15 min604 flights57.9%
15–29 min late109 flights10.5%
30–59 min late65 flights6.2%
1–2 hours late20 flights1.9%
2+ hours late14 flights1.3%

Scale runs 0% to 100%.

Share of 1,043 completed flights by arrival against schedule.

A late pushback is often recovered here: of 239 departures that left 15 minutes late or more, 102 still arrived on time. In the other direction, 71 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 AUS.

The worst days

Worst days for Alaska on SEA to AUS

The latest arrival of the period was on 21 June 2026, 5 hours 10 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).

The latest arrivals of Alaska on SEA to AUS in the period
Date	Arrived late by	Largest filed cause
21 June 2026	5 hours 10 minutes	Late-arriving aircraft
25 July 2026	4 hours 31 minutes	Carrier
9 February 2026	4 hours 3 minutes	Carrier
28 December 2025	3 hours 45 minutes	Carrier
25 August 2026	3 hours 37 minutes	Carrier

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 9,176 reported delay minutes.

Carrier
35%
National Airspace System
35%
Late-arriving aircraft
26%
Extreme weather
4%

35% 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 3,173 minutes out of 9,176, against a national NAS share of 21%. The split is drawn from 9,176 reported delay minutes.

The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,251 of the 9,176 delay minutes reported here.

Cancellations are rare at 0.67%, below the national 1.89% 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 3.3% land an hour or more behind schedule, against 8.3% 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 runs 81.8% on time across 1,051 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.

One caution: this is a thin sample. 1,051 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 Alaska on SEA to AUS

Put together: treat all of this as provisional. 1,051 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 80.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,043 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures