Carrier route record
WNAUS→SAN
Southwest Airlines · Austin to San Diego
- Flights
- 1,422
- Period
- July 2025 to June 2026
- Share of route
- 56%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on AUS to SAN sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land about 55 minutes behind schedule. That rests on 1,422 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.6%, so Southwest on AUS to SAN runs 7 points behind the country as a whole. Across a thousand flights that is about 72 extra late arrivals.
Key figures
On time
70.4%
Arrivals under 15 minutes late, of 1,410 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
National rate is 1.81%
Whole route
75.0%
Every carrier on AUS to SAN, 2,545 flights
These figures cover 1,422 flights between July 2025 and June 2026. Beyond the headline rate, 8.6% 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 SAN
Southwest flew 1,422 of the 2,545 flights on AUS to SAN, most of the route. Its 70.4% on time is 5 points worse than the route as a whole, which runs 75.0%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 81.9% to Southwest at 70.4%. 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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 1,000 | 81.9% | 63 min | 1.50% | B |
| Frontier Airlinesthin sample | 123 | 73.3% | 94 min | 2.44% | C |
| Southwest Airlines (this page) | 1,422 | 70.4% | 54 min | 0.63% | C+ |
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 45 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am303 flights96.4%
- 8am–11am113 flights85.6%
- 11am–2pm263 flights77.1%
- 2pm–5pm182 flights55.5%
- 5pm–8pm240 flights51.0%
- 8pm–5am321 flights57.6%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 51.0% on time, against 96.4% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 321 flights scheduled in it.
Across the year
Southwest on AUS to SAN through the year
June is the worst month at 50.8% on time, 30 points below March, the best at 80.8%. 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. May was the busiest month here, with 131 flights.
Across the week, Saturday is the strongest day at 80.2% on time and Thursday the weakest at 62.3%. 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. Late-arriving aircraft accounts for 62% of the 23,000 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.
- 62%Late-arriving aircraft
- 24%Carrier
- 11%National Airspace System
- 2%Extreme weather
62% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 23,000 reported delay minutes here, that single category outweighs weather by 29 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 22,743 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 96.4% on time here.
Cancellations are rare at 0.63%, 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
8.6% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.
The 1,164 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 68.2% on time across 1,429 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.
The sample behind these figures is 1,422 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Southwest on AUS to SAN
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 80.8% on time and June 50.8%, a swing of 30 points. If the dates move at all, move them out of June before you think about anything else. 1,410 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to SAN, every carrier
- Southwest on SAN to AUS, the return leg
- SkyWest Airlines on AUS to SAN81.9%
- Frontier Airlines on AUS to SAN73.3%
- Southwest Airlines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- San Diego International (SAN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.