Carrier route record
WNSJC→LAX
Southwest Airlines · San Jose to Los Angeles
- Flights
- 1,823
- Period
- July 2025 to June 2026
- Share of route
- 41%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SJC to LAX lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That is a workable record, not a spotless one. That rests on 1,823 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 2,053 at 92.6% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on SJC to LAX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.9%
Arrivals under 15 minutes late, of 1,815 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.44%
National rate is 1.81%
Whole route
86.6%
Every carrier on SJC to LAX, 4,433 flights
These figures cover 1,823 flights between July 2025 and June 2026. The median arrival is 5 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 SJC to LAX
Southwest flew 1,823 of the 4,433 flights on SJC to LAX, about 41% of it. Its 78.9% on time is 8 points worse than the route as a whole, which runs 86.6%. Ranked by on-time rate it is number five of six carriers on the route, where the range runs from United at 100.0% to American at 66.7%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: half 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 |
|---|---|---|---|---|---|
| United Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| SkyWest Airlines | 2,053 | 92.6% | 73 min | 0.39% | A+ |
| Delta Air Lines | 454 | 92.3% | 50 min | 3.08% | A− |
| Frontier Airlinesthin sample | 96 | 82.6% | 56 min | 4.17% | B− |
| Southwest Airlines (this page) | 1,823 | 78.9% | 47 min | 0.44% | B+ |
| American Airlinesthin sample | 6 | 66.7% | 29 min | 0.00% | C+ |
Delta Air Lines cancels 3.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after 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 33 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–8am226 flights96.4%
- 8am–11am417 flights92.0%
- 11am–2pm271 flights80.8%
- 2pm–5pm338 flights73.6%
- 5pm–8pm311 flights66.1%
- 8pm–5am260 flights63.1%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.1% 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 8am–11am window is the busiest, with 417 flights scheduled in it.
Across the year
Southwest on SJC to LAX through the year
June is the worst month at 62.0% on time, 32 points below January, the best at 93.9%. 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 179 flights.
Across the week, Saturday is the strongest day at 85.8% on time and Friday the weakest at 71.6%. 14 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 65% of the 18,000 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.
- 65%Late-arriving aircraft
- 23%Carrier
- 11%National Airspace System
- 1%Security
- 0%Extreme weather
65% 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 18,000 reported delay minutes here, that single category outweighs weather by 65 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 18,137 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 0.44%, 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
5.4% 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 45 minutes, which a normal layover absorbs.
At 308 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 runs 81.5% on time across 1,822 flights, within 3 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 1,823 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 SJC to LAX
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 93.9% on time and June 62.0%, a swing of 32 points. If the dates move at all, move them out of June before you think about anything else. 1,815 completed flights over 12 months sit behind that.
Related
Where to go next
- SJC to LAX, every carrier
- Southwest on LAX to SJC, the return leg
- SkyWest Airlines on SJC to LAX92.6%
- Delta Air Lines on SJC to LAX92.3%
- Southwest Airlines network-wide record
- Norman Y. Mineta San Jose International (SJC) delay statistics
- Los Angeles International (LAX) 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.