Carrier route record
DLSEA→AUS
Delta Air Lines · Seattle to Austin
- Flights
- 950
- Period
- September 2025 to August 2026
- Share of route
- 45%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta 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 an hour on average. That rests on 950 flights, with a median arrival 8 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on SEA to AUS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.1%
Arrivals under 15 minutes late, of 939 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
1.05%
National rate is 1.89%
Whole route
78.5%
Every carrier on SEA to AUS, 2,090 flights
These figures cover 950 flights between September 2025 and August 2026. The median arrival is 8 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Delta against every carrier on SEA to AUS
Delta flew 950 of the 2,090 flights on SEA to AUS, about 45% of it. 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 first 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 950 | 80.1% | 67 min | 1.05% | B |
| Alaska Airlines | 1,051 | 80.1% | 44 min | 0.67% | B+ |
| Southwest Airlinesthin sample | 89 | 42.7% | 57 min | 0.00% | F+ |
Flight by flight
Delta 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 Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against half a point between the best and worst carrier.
- 5am–8am278 flights89.1%
- 8am–11am113 flights87.3%
- 11am–2pm248 flights75.0%
- 2pm–5pm—
- 5pm–8pm311 flights73.5%
- 8pm–5am—
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 89.1% of the time, against 73.5% for the evening window. That is 16 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 311 flights scheduled in it.
Across the year
Delta on SEA to AUS through the year
July is the worst month at 71.0% on time, 23 points below January, the best at 93.8%. 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 93 flights.
Across the week, Tuesday is the strongest day at 88.5% on time and Friday the weakest at 72.8%, a spread of 16 points.
Arrival by arrival
How late Delta on SEA to AUS runs when it is late
Delta on SEA to AUS often beats the schedule: 313 of 939 completed flights, 33%, arrived 15 minutes or more early. The 187 late arrivals split 73 under half an hour, 47 between 30 and 60 minutes, and 67 an hour or more.
- 15+ min early313 flights33.3%
- Within 15 min439 flights46.8%
- 15–29 min late73 flights7.8%
- 30–59 min late47 flights5.0%
- 1–2 hours late39 flights4.2%
- 2+ hours late28 flights3.0%
Scale runs 0% to 100%.
Share of 939 completed flights by arrival against schedule.
43 of 167 late departures made up the time and arrived on time, 26% of them. In the other direction, 63 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 Delta on SEA to AUS
The latest arrival of the period was on 11 October 2025, 8 hours 16 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 October 2025 | 8 hours 16 minutes | Carrier |
| 5 November 2025 | 5 hours 27 minutes | Carrier |
| 13 March 2026 | 5 hours 18 minutes | Late-arriving aircraft |
| 13 March 2026 | 4 hours 37 minutes | Extreme weather |
| 24 August 2026 | 4 hours 33 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 52% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Carrier
- 25%Late-arriving aircraft
- 20%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,526 of the 13,000 delay minutes reported here. The split is drawn from 12,505 reported delay minutes.
Cancellations sit at 1.05% against a national 1.89%, which is ordinary. Diversions add another 0.11%.
Connections and stage length
What a delay here costs
7.1% 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 about an hour, 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 83.8% on time across 949 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.
One caution: this is a thin sample. 950 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 Delta on SEA to AUS
Put together: treat all of this as provisional. 950 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. 939 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to AUS, every carrier
- Delta on AUS to SEA, the return leg
- Alaska Airlines on SEA to AUS80.1%
- Delta Air Lines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
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.