Carrier route record
WNLAS→SAN
Southwest Airlines · Las Vegas to San Diego
- Flights
- 3,738
- Period
- July 2025 to June 2026
- Share of route
- 64%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAS to SAN draws a D+. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is about 50 minutes behind schedule. Build slack into anything you connect to. That rests on 3,738 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,492 at 74.6% on time.
The national on-time rate over the same period is 77.6%, so Southwest on LAS to SAN runs 15 points behind the country as a whole. Across a thousand flights that is about 151 extra late arrivals.
Key figures
On time
62.5%
Arrivals under 15 minutes late, of 3,697 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.99%
National rate is 1.81%
Whole route
66.7%
Every carrier on LAS to SAN, 5,877 flights
These figures cover 3,738 flights between July 2025 and June 2026. Beyond the headline rate, 9.0% 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 LAS to SAN
Southwest flew 3,738 of the 5,877 flights on LAS to SAN, most of the route. Its 62.5% on time is 4 points worse than the route as a whole, which runs 66.7%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from Alaska at 100.0% to Southwest at 62.5%. Two 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 74.6% of the time; Frontier Airlines manages 68.2%. 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 |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Spirit Airlinesthin sample | 257 | 78.7% | 72 min | 1.17% | B |
| SkyWest Airlines | 1,492 | 74.6% | 63 min | 1.34% | C |
| Frontier Airlines | 389 | 68.2% | 91 min | 1.29% | C |
| Southwest Airlines (this page) | 3,738 | 62.5% | 50 min | 0.99% | D+ |
SkyWest leads Frontier by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 38 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am592 flights88.3%
- 8am–11am682 flights68.9%
- 11am–2pm668 flights57.3%
- 2pm–5pm687 flights59.0%
- 5pm–8pm560 flights49.9%
- 8pm–5am549 flights50.2%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 49.9% on time, against 88.3% 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 2pm–5pm window is the busiest, with 687 flights scheduled in it.
Across the year
Southwest on LAS to SAN through the year
June is the worst month at 49.7% on time, 23 points below January, the best at 72.4%. 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 75.2% on time and Thursday the weakest at 53.3%. 22 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 68,000 reported delay minutes.
- 40%Late-arriving aircraft
- 30%National Airspace System
- 29%Carrier
- 1%Extreme weather
- 0%Security
40% 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 68,000 reported delay minutes here, that single category outweighs weather by 30 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 68,464 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 88.3% on time here.
Cancellations sit at 0.99% against a national 1.81%, which is ordinary. Diversions add another 0.11%.
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. 9.0% 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 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 74.7% on time across 3,730 flights, 12 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 12 points of difference.
The sample behind these figures is 3,738 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 SAN
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 72.4% on time and June 49.7%, a swing of 23 points. If the dates move at all, move them out of June before you think about anything else. 3,697 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to SAN, every carrier
- Southwest on SAN to LAS, the return leg
- Spirit Airlines on LAS to SAN78.7%
- SkyWest Airlines on LAS to SAN74.6%
- Frontier Airlines on LAS to SAN68.2%
- Southwest Airlines network-wide record
- Harry Reid International (LAS) 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.