Carrier route record
WNLAS→SAT
Southwest Airlines · Las Vegas to San Antonio
- Flights
- 1,569
- Period
- September 2025 to August 2026
- Share of route
- 77%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAS to SAT sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 1,569 flights, with a median arrival 1 minute late.
The national on-time rate over the same period is 77.3%, so Southwest on LAS to SAT runs 5 points behind the country as a whole. Across a thousand flights that is about 52 extra late arrivals.
Key figures
On time
72.1%
Arrivals under 15 minutes late, of 1,561 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.25%
National rate is 1.89%
Whole route
74.4%
Every carrier on LAS to SAT, 2,032 flights
These figures cover 1,569 flights between September 2025 and August 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.
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 LAS to SAT
Southwest flew 1,569 of the 2,032 flights on LAS to SAT, most of the route. Its 72.1% on time is 2 points worse than the route as a whole, which runs 74.4%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Spirit at 83.5% to Southwest at 72.1%. Two 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 |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 159 | 83.5% | 96 min | 0.63% | B+ |
| Frontier Airlinesthin sample | 304 | 81.5% | 62 min | 0.66% | B+ |
| Southwest Airlines (this page) | 1,569 | 72.1% | 49 min | 0.25% | C+ |
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 45 points, against half a point between the best and worst carrier.
- 5am–8am294 flights95.9%
- 8am–11am284 flights79.9%
- 11am–2pm263 flights76.4%
- 2pm–5pm266 flights58.3%
- 5pm–8pm317 flights60.5%
- 8pm–5am145 flights51.1%
Scale runs 45% to 100%.
The 8pm–5am window is where this operation falls apart: 51.1% on time, against 95.9% 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 5pm–8pm window is the busiest, with 317 flights scheduled in it.
Across the year
Southwest on LAS to SAT through the year
July is the worst month at 56.3% on time, 27 points below February, the best at 83.6%. 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. December was the busiest month here, with 150 flights.
Across the week, Saturday is the strongest day at 81.2% on time and Sunday the weakest at 63.1%, a spread of 18 points.
Arrival by arrival
How late Southwest on LAS to SAT runs when it is late
The 435 late arrivals split 188 under half an hour, 140 between 30 and 60 minutes, and 107 an hour or more.
- 15+ min early178 flights11.4%
- Within 15 min948 flights60.7%
- 15–29 min late188 flights12.0%
- 30–59 min late140 flights9.0%
- 1–2 hours late75 flights4.8%
- 2+ hours late32 flights2.0%
Scale runs 0% to 100%.
Share of 1,561 completed flights by arrival against schedule.
130 of 519 late departures made up the time and arrived on time, 25% of them. 46 flights left on time and still arrived late.
The worst days
Worst days for Southwest on LAS to SAT
The latest arrival of the period was on 10 October 2025, 4 hours 27 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in October 2025.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 October 2025 | 4 hours 27 minutes | Late-arriving aircraft |
| 1 August 2026 | 4 hours 18 minutes | Late-arriving aircraft |
| 26 October 2025 | 4 hours 14 minutes | Late-arriving aircraft |
| 18 September 2025 | 4 hours 6 minutes | Late-arriving aircraft |
| 10 October 2025 | 3 hours 49 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 55% of the 21,000 delay minutes carriers reported here, and the remaining four split what is left.
- 55%Late-arriving aircraft
- 35%Carrier
- 10%National Airspace System
- 0%Security
- 0%Extreme weather
55% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 21,000 reported delay minutes here, that single category outweighs weather by 55 to one. The split is drawn from 21,216 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,404 of the 21,000 delay minutes reported here.
Cancellations are rare at 0.25%, 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
6.9% 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 roughly 50 minutes, which a normal layover absorbs.
The 1,069 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.
The return leg is a different operation and performs like one: it runs 79.3% on time across 1,587 flights, 7 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 7 points of difference.
The sample behind these figures is 1,569 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 LAS to SAT
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 83.6% on time and July 56.3%, a swing of 27 points. If the dates move at all, move them out of July before you think about anything else. 1,561 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to SAT, every carrier
- Southwest on SAT to LAS, the return leg
- Spirit Airlines on LAS to SAT83.5%
- Frontier Airlines on LAS to SAT81.5%
- Southwest Airlines network-wide record
- Harry Reid International (LAS) delay statistics
- San Antonio International (SAT) delay statistics
- Why the first flight of the morning is statistically safest
- 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.