Carrier route record
WNSAT→LAX
Southwest Airlines · San Antonio to Los Angeles
- Flights
- 337
- Period
- July 2025 to June 2026
- Share of route
- 18%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SAT to LAX sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 337 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 697 at 90.3% on time.
The national on-time rate over the same period is 77.6%, so Southwest on SAT to LAX runs 4 points behind the country as a whole. Across a thousand flights that is about 44 extra late arrivals.
Key figures
On time
73.2%
Arrivals under 15 minutes late, of 336 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
Whole route
86.6%
Every carrier on SAT to LAX, 1,881 flights
These figures cover 337 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Southwest against every carrier on SAT to LAX
Southwest flew 337 of the 1,881 flights on SAT to LAX, about 18% of it. Its 73.2% on time is 13 points worse than the route as a whole, which runs 86.6%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from SkyWest at 90.3% to Southwest at 73.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 697 | 90.3% | 124 min | 0.29% | A+ |
| Delta Air Lines | 684 | 89.4% | 107 min | 0.44% | A+ |
| Spirit Airlinesthin sample | 163 | 86.8% | 87 min | 2.45% | A |
| Southwest Airlines (this page)thin sample | 337 | 73.2% | 48 min | 0.00% | C+ |
No carrier stands out. SkyWest tops the table at 90.3%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Departure window
When Southwest runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 337 flights.
- 5am–8am—
- 8am–11am2 flights—
- 11am–2pm143 flights74.8%
- 2pm–5pm146 flights77.9%
- 5pm–8pm26 flights—
- 8pm–5am20 flights—
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The 2pm–5pm window is the strongest at 77.9% on time. The full set of windows spans 3 points.
Across the year
Southwest on SAT to LAX through the year
September is the best month on the calendar at 93.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 33 flights.
Across the week, Monday is the strongest day at 77.1% on time and Tuesday the weakest at 71.1%. 6 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 63% of the 4,313 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%Late-arriving aircraft
- 29%Carrier
- 8%National Airspace System
63% 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 4,313 reported delay minutes here, that single category outweighs weather by 63 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 4,313 reported delay minutes.
Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
7.4% 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 roughly 50 minutes, which a normal layover absorbs.
The 1,211 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 is a different operation and performs like one: it runs 68.5% on time across 337 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 337 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 SAT to LAX
Put together: treat all of this as provisional. 337 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 73.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 336 completed flights over 12 months sit behind that.
Related
Where to go next
- SAT to LAX, every carrier
- Southwest on LAX to SAT, the return leg
- SkyWest Airlines on SAT to LAX90.3%
- Delta Air Lines on SAT to LAX89.4%
- Spirit Airlines on SAT to LAX86.8%
- Southwest Airlines network-wide record
- San Antonio International (SAT) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
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.