Carrier route record
WNSAN→LAS
Southwest Airlines · San Diego to Las Vegas
- Flights
- 3,730
- Period
- July 2025 to June 2026
- Share of route
- 64%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SAN to LAS sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land roughly 55 minutes behind schedule. That rests on 3,730 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,491 at 78.9% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on SAN to LAS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.7%
Arrivals under 15 minutes late, of 3,681 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
1.21%
National rate is 1.81%
Whole route
75.6%
Every carrier on SAN to LAS, 5,868 flights
These figures cover 3,730 flights between July 2025 and June 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Southwest against every carrier on SAN to LAS
Southwest flew 3,730 of the 5,868 flights on SAN to LAS, most of the route. Its 74.7% on time is about level with the route as a whole at 75.6%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Spirit at 84.2% to Frontier at 66.6%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 78.9% of the time; Frontier Airlines manages 66.6%. Sample sizes sit next to every figure, because a two-point gap across 389 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 258 | 84.2% | 65 min | 1.94% | B |
| SkyWest Airlines | 1,491 | 78.9% | 70 min | 1.34% | B |
| Southwest Airlines (this page) | 3,730 | 74.7% | 53 min | 1.21% | C |
| Frontier Airlines | 389 | 66.6% | 95 min | 2.06% | C |
The spread between SkyWest and Frontier 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 34 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am489 flights96.3%
- 8am–11am713 flights87.1%
- 11am–2pm632 flights73.8%
- 2pm–5pm753 flights62.7%
- 5pm–8pm620 flights67.5%
- 8pm–5am523 flights63.7%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 96.3% of the time, against 62.7% for the afternoon window. That is 34 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 753 flights scheduled in it.
Across the year
Southwest on SAN to LAS through the year
June is the worst month at 64.6% on time, 18 points below January, the best at 82.2%. 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. October was the busiest month here, with 333 flights.
Across the week, Wednesday is the strongest day at 84.2% on time and Friday the weakest at 64.6%. 20 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 60% of the 49,000 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.
- 60%Late-arriving aircraft
- 20%National Airspace System
- 17%Carrier
- 3%Extreme weather
- 0%Security
60% 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 49,000 reported delay minutes here, that single category outweighs weather by 24 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 49,117 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 96.3% on time here.
Cancellations sit at 1.21% against a national 1.81%, which is ordinary. Diversions add another 0.11%.
Connections and stage length
What a delay here costs
7.2% 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 55 minutes, which a normal layover absorbs.
At 258 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 62.5% on time across 3,738 flights, 12 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 12 points of difference.
The sample behind these figures is 3,730 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 SAN to LAS
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 82.2% on time and June 64.6%, a swing of 18 points. If the dates move at all, move them out of June before you think about anything else. 3,681 completed flights over 12 months sit behind that.
Related
Where to go next
- SAN to LAS, every carrier
- Southwest on LAS to SAN, the return leg
- Spirit Airlines on SAN to LAS84.2%
- SkyWest Airlines on SAN to LAS78.9%
- Frontier Airlines on SAN to LAS66.6%
- Southwest Airlines network-wide record
- San Diego International (SAN) delay statistics
- Harry Reid International (LAS) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.