Carrier route record
WNAUS→SFO
Southwest Airlines · Austin to San Francisco
- Flights
- 411
- Period
- September 2025 to August 2026
- Share of route
- 15%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on AUS to SFO earns a D+, which is as low as this site's scale goes for a reason. Only 57.0% of flights arrive inside the 15-minute window, 20 points worse than the national rate of 77.3%. Late arrivals average about 55 minutes. Treat any tight connection here as a coin flip. That rests on 411 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,638 at 75.5% on time.
The national on-time rate over the same period is 77.3%, so Southwest on AUS to SFO runs 20 points behind the country as a whole. Across a thousand flights that is about 203 extra late arrivals.
Key figures
On time
57.0%
Arrivals under 15 minutes late, of 409 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.49%
National rate is 1.89%
Whole route
72.4%
Every carrier on AUS to SFO, 2,788 flights
These figures cover 411 flights between September 2025 and August 2026. Beyond the headline rate, 12.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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
Southwest against every carrier on AUS to SFO
Southwest flew 411 of the 2,788 flights on AUS to SFO, about 15% of it. Its 57.0% on time is 15 points worse than the route as a whole, which runs 72.4%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from SkyWest at 84.6% to Southwest at 57.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 75.5% of the time; Delta Air Lines manages 69.2%. Sample sizes sit next to every figure, because a two-point gap across 500 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 13 | 84.6% | 17 min | 0.00% | B+ |
| Alaska Airlinesthin sample | 226 | 84.4% | 55 min | 0.88% | B+ |
| United Airlines | 1,638 | 75.5% | 76 min | 0.37% | B+ |
| Delta Air Lines | 500 | 69.2% | 63 min | 1.00% | C |
| Southwest Airlines (this page) | 411 | 57.0% | 55 min | 0.49% | D+ |
United leads Delta by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 points, against 6 points between the best and worst carrier.
- 5am–8am—
- 8am–11am131 flights59.2%
- 11am–2pm159 flights62.7%
- 2pm–5pm87 flights41.4%
- 5pm–8pm34 flights61.8%
- 8pm–5am—
Scale runs 35% to 70%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 62.7% on time, ahead of 2pm–5pm at 41.4%. 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 11am–2pm window is the busiest, with 159 flights scheduled in it.
Across the year
Southwest on AUS to SFO through the year
October is the best month on the calendar at 77.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 54 flights.
Across the week, Tuesday is the strongest day at 71.9% on time and Wednesday the weakest at 51.6%, a spread of 20 points.
Arrival by arrival
How late Southwest on AUS to SFO runs when it is late
The 176 late arrivals split 55 under half an hour, 69 between 30 and 60 minutes, and 52 an hour or more.
- 15+ min early53 flights13.0%
- Within 15 min180 flights44.0%
- 15–29 min late55 flights13.4%
- 30–59 min late69 flights16.9%
- 1–2 hours late39 flights9.5%
- 2+ hours late13 flights3.2%
Scale runs 0% to 100%.
Share of 409 completed flights by arrival against schedule.
24 of 176 late departures made up the time and arrived on time, 14% of them. In the other direction, 24 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 SFO.
The worst days
Worst days for Southwest on AUS to SFO
The latest arrival of the period was on 14 July 2026, 6 hours 8 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across July, May, November and February, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 July 2026 | 6 hours 8 minutes | Carrier |
| 14 July 2026 | 3 hours 9 minutes | Late-arriving aircraft |
| 19 May 2026 | 3 hours 7 minutes | Late-arriving aircraft |
| 13 November 2025 | 2 hours 46 minutes | National Airspace System |
| 15 February 2026 | 2 hours 43 minutes | National Airspace System |
Delay causes
Why Southwest runs late on this route
National Airspace System accounts for 55% of the 9,617 delay minutes carriers reported here, and the remaining four split what is left.
- 55%National Airspace System
- 25%Late-arriving aircraft
- 20%Carrier
55% 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 5,280 minutes out of 9,617, against a national NAS share of 21%. The split is drawn from 9,617 reported delay minutes.
Cancellations are rare at 0.49%, 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
12.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,504 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 40.1% on time across 411 flights, 17 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 17 points of difference.
One caution: this is a thin sample. 411 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 Southwest on AUS to SFO
Put together: treat all of this as provisional. 411 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 57.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 409 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to SFO, every carrier
- Southwest on SFO to AUS, the return leg
- Alaska Airlines on AUS to SFO84.4%
- United Airlines on AUS to SFO75.5%
- Delta Air Lines on AUS to SFO69.2%
- Southwest Airlines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- San Francisco International (SFO) delay statistics
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.05 million flight records
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.