Carrier route record
WNSJC→LAX
Southwest Airlines · San Jose to Los Angeles
- Flights
- 1,867
- Period
- September 2025 to August 2026
- Share of route
- 42%
- Carriers
- 6
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SJC to LAX lands a B+, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That rests on 1,867 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,809 at 91.7% on time.
The US average over the same twelve months is 77.3%, 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
76.8%
Arrivals under 15 minutes late, of 1,855 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.64%
National rate is 1.89%
Whole route
85.0%
Every carrier on SJC to LAX, 4,470 flights
These figures cover 1,867 flights between September 2025 and August 2026. The median arrival is 3 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.
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Carrier by carrier
Southwest against every carrier on SJC to LAX
Southwest flew 1,867 of the 4,470 flights on SJC to LAX, about 42% of it. Its 76.8% on time is 8 points worse than the route as a whole, which runs 85.0%. Ranked by on-time rate it is number four 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 | 1,809 | 91.7% | 76 min | 0.44% | A+ |
| Delta Air Lines | 649 | 91.6% | 57 min | 2.31% | A |
| Southwest Airlines (this page) | 1,867 | 76.8% | 47 min | 0.64% | B+ |
| Frontier Airlinesthin sample | 138 | 75.8% | 43 min | 4.35% | B− |
| American Airlinesthin sample | 6 | 66.7% | 29 min | 0.00% | C+ |
No carrier stands out. SkyWest tops the table at 91.7%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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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 35 points, against half a point between the best and worst carrier.
- 5am–8am258 flights94.1%
- 8am–11am398 flights90.7%
- 11am–2pm280 flights81.0%
- 2pm–5pm355 flights69.7%
- 5pm–8pm315 flights64.6%
- 8pm–5am261 flights58.8%
Scale runs 50% to 100%.
The 8pm–5am window is where this operation falls apart: 58.8% on time, against 94.1% 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 398 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. July was the busiest month here, with 182 flights.
Across the week, Wednesday is the strongest day at 84.9% on time and Friday the weakest at 69.8%, a spread of 15 points.
Arrival by arrival
How late Southwest on SJC to LAX runs when it is late
The 430 late arrivals split 176 under half an hour, 144 between 30 and 60 minutes, and 110 an hour or more.
- 15+ min early353 flights19.0%
- Within 15 min1,072 flights57.8%
- 15–29 min late176 flights9.5%
- 30–59 min late144 flights7.8%
- 1–2 hours late87 flights4.7%
- 2+ hours late23 flights1.2%
Scale runs 0% to 100%.
Share of 1,855 completed flights by arrival against schedule.
98 of 478 late departures made up the time and arrived on time, 21% of them. 50 flights left on time and still arrived late.
The worst days
Worst days for Southwest on SJC to LAX
The latest arrival of the period was on 27 March 2026, 4 hours 1 minute behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 27 March 2026 | 4 hours 1 minute | Late-arriving aircraft |
| 19 December 2025 | 3 hours 34 minutes | Late-arriving aircraft |
| 29 June 2026 | 2 hours 55 minutes | Late-arriving aircraft |
| 31 March 2026 | 2 hours 49 minutes | Late-arriving aircraft |
| 7 May 2026 | 2 hours 40 minutes | Carrier |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 66% of the 20,000 delay minutes carriers reported here, and the remaining four split what is left.
- 66%Late-arriving aircraft
- 20%Carrier
- 14%National Airspace System
- 0%Security
- 0%Extreme weather
66% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 20,000 reported delay minutes here, that single category outweighs weather by 66 to one. The split is drawn from 20,064 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 94.1% on time here.
Cancellations are rare at 0.64%, 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
5.9% 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 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 is a different operation and performs like one: it runs 80.6% on time across 1,871 flights, 4 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 4 points of difference.
The sample behind these figures is 1,867 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. 1,855 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 LAX91.7%
- Delta Air Lines on SJC to LAX91.6%
- Frontier Airlines on SJC to LAX75.8%
- 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 7.05 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.