Carrier route record
WNAUS→SFO
Southwest Airlines · Austin to San Francisco
- Flights
- 344
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on AUS to SFO draws a D+. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 344 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,655 at 78.8% on time.
The national on-time rate over the same period is 77.6%, so Southwest on AUS to SFO runs 15 points behind the country as a whole. Across a thousand flights that is about 150 extra late arrivals.
Key figures
On time
62.6%
Arrivals under 15 minutes late, of 342 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
0.58%
National rate is 1.81%
Whole route
74.9%
Every carrier on AUS to SFO, 2,795 flights
These figures cover 344 flights between July 2025 and June 2026. Beyond the headline rate, 10.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Southwest against every carrier on AUS to SFO
Southwest flew 344 of the 2,795 flights on AUS to SFO, about 12% of it. Its 62.6% on time is 12 points worse than the route as a whole, which runs 74.9%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 78.8% to Southwest at 62.6%. 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 78.8% of the time; Delta Air Lines manages 66.7%. Sample sizes sit next to every figure, because a two-point gap across 444 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,655 | 78.8% | 74 min | 0.79% | B+ |
| Alaska Airlinesthin sample | 344 | 78.8% | 60 min | 1.16% | B |
| SkyWest Airlinesthin sample | 8 | 75.0% | 17 min | 0.00% | B+ |
| Delta Air Lines | 444 | 66.7% | 59 min | 1.13% | C |
| Southwest Airlines (this page)thin sample | 344 | 62.6% | 51 min | 0.58% | D+ |
The spread between United and Delta is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.
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 29 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am129 flights70.3%
- 11am–2pm151 flights64.0%
- 2pm–5pm51 flights41.2%
- 5pm–8pm13 flights—
- 8pm–5am—
Scale runs 35% to 75%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 70.3% of the time, against 41.2% for the afternoon window. That is 29 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 151 flights scheduled in it.
Across the year
Southwest on AUS to SFO through the year
- Jul–Sep 202557 flights73.7%
- Oct–Dec 202592 flights76.1%
- Jan–Mar 202686 flights76.2%
- Apr–Jun 2026109 flights34.9%
Scale runs 25% to 80%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 62.6% on time across 344 flights.
Southwest on AUS to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 76.2% on time and its weakest Apr–Jun 2026 at 34.9%, a swing of 41 points on roughly 86 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Tuesday is the strongest day at 75.0% on time and Friday the weakest at 56.9%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. National Airspace System accounts for 63% of the 6,552 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 63%National Airspace System
- 20%Late-arriving aircraft
- 17%Carrier
63% 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 4,115 minutes out of 6,552, against a national NAS share of 21%. The split is drawn from 6,552 reported delay minutes.
Cancellations are rare at 0.58%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 44.8% on time across 344 flights, 18 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 18 points of difference.
One caution: this is a thin sample. 344 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. 344 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 62.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 342 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
- United Airlines on AUS to SFO78.8%
- Alaska Airlines on AUS to SFO78.8%
- Delta Air Lines on AUS to SFO66.7%
- Southwest Airlines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- San Francisco International (SFO) delay statistics
- Same route, different airline: where the carrier you pick matters most
- How often a connection fails at the major US hubs
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.