Carrier route record

ASAUS→SEA

Alaska Airlines · Austin to Seattle

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 AUS to SEA lands a B+, 5 points better than the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That rests on 1,051 flights, with a median arrival 7 minutes early.

Set against the rest of the country, Alaska's AUS to SEA record is 5 points better than the US average of 77.3%. That gap is worth roughly 45 fewer late arrivals for every thousand flights.

On time

81.8%

Arrivals under 15 minutes late, of 1,041 completed flights

Avg delay

50 min

Across delayed arrivals only, not all flights

Cancelled

0.76%

National rate is 1.89%

Whole route

81.3%

Every carrier on AUS to SEA, 2,089 flights

These figures cover 1,051 flights between September 2025 and August 2026. The median arrival is 7 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 AUS to SEA

Alaska flew 1,051 of the 2,089 flights on AUS to SEA, most of the route. Its 81.8% on time is about level with the route as a whole at 81.3%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 83.8% to Southwest at 48.9%. 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
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	949	83.8%	82 min	0.95%	B+
Alaska Airlines (this page)	1,051	81.8%	50 min	0.76%	B+
Southwest Airlinesthin sample	89	48.9%	38 min	1.12%	F

Flight by flight

Alaska flight numbers on AUS to SEA

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 matters more here than the choice of carrier. The gap between the best and worst window is 11 points, against half a point between the best and worst carrier.

5am–8am218 flights85.6%
8am–11am146 flights84.9%
11am–2pm164 flights85.3%
2pm–5pm201 flights83.8%
5pm–8pm298 flights74.9%
8pm–5am24 flights—

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

Book the early departure. Flights leaving between 5am–8am arrive on time 85.6% of the time, against 74.9% for the evening window. That is 11 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 298 flights scheduled in it.

Across the year

Alaska on AUS to SEA through the year

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. May was the busiest month here, with 93 flights.

Across the week, Saturday is the strongest day at 87.0% on time and Thursday the weakest at 76.6%, a spread of 10 points.

Arrival by arrival

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

Alaska on AUS to SEA often beats the schedule: 318 of 1,041 completed flights, 31%, arrived 15 minutes or more early. The 189 late arrivals split 91 under half an hour, 54 between 30 and 60 minutes, and 44 an hour or more.

15+ min early318 flights30.5%
Within 15 min534 flights51.3%
15–29 min late91 flights8.7%
30–59 min late54 flights5.2%
1–2 hours late29 flights2.8%
2+ hours late15 flights1.4%

Scale runs 0% to 100%.

Share of 1,041 completed flights by arrival against schedule.

A late pushback is often recovered here: of 208 departures that left 15 minutes late or more, 78 still arrived on time. In the other direction, 59 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 SEA.

The worst days

Worst days for Alaska on AUS to SEA

The latest arrival of the period was on 12 February 2026, 5 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.

The latest arrivals of Alaska on AUS to SEA in the period
Date	Arrived late by	Largest filed cause
12 February 2026	5 hours 26 minutes	Carrier
21 June 2026	5 hours 7 minutes	Late-arriving aircraft
25 May 2026	4 hours 32 minutes	Carrier
9 February 2026	3 hours 35 minutes	Late-arriving aircraft
19 December 2025	3 hours 22 minutes	Late-arriving aircraft

Delay causes

Why Alaska runs late on this route

Late-arriving aircraft accounts for 44% of the 9,389 delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
44%
National Airspace System
30%
Carrier
19%
Extreme weather
4%
Security
2%

44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,389 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 9,389 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 85.6% on time here.

Cancellations are rare at 0.76%, 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 4.2% 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 80.1% 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 AUS to SEA

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 81.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,041 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