Carrier route record
WNLAX→SJC
Southwest Airlines · Los Angeles to San Jose
- Flights
- 1,871
- 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 LAX to SJC lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That rests on 1,871 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,805 at 90.7% on time.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on LAX to SJC from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.6%
Arrivals under 15 minutes late, of 1,854 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.91%
National rate is 1.89%
Whole route
85.6%
Every carrier on LAX to SJC, 4,471 flights
These figures cover 1,871 flights between September 2025 and August 2026. The median arrival is 8 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 LAX to SJC
Southwest flew 1,871 of the 4,471 flights on LAX to SJC, about 42% of it. Its 80.6% on time is 5 points worse than the route as a whole, which runs 85.6%. 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: 4 points 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 | 1,805 | 90.7% | 58 min | 0.39% | A+ |
| Delta Air Lines | 650 | 86.9% | 59 min | 2.15% | A |
| Southwest Airlines (this page) | 1,871 | 80.6% | 50 min | 0.91% | B+ |
| Frontier Airlinesthin sample | 138 | 80.5% | 50 min | 3.62% | B− |
| American Airlinesthin sample | 6 | 66.7% | 39 min | 0.00% | C+ |
No carrier stands out. SkyWest tops the table at 90.7%, 4 points 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 40 points, against 4 points between the best and worst carrier.
- 5am–8am331 flights96.3%
- 8am–11am319 flights92.3%
- 11am–2pm281 flights84.6%
- 2pm–5pm314 flights84.7%
- 5pm–8pm388 flights66.7%
- 8pm–5am238 flights56.5%
Scale runs 50% to 100%.
The 8pm–5am window is where this operation falls apart: 56.5% on time, against 96.3% 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 5pm–8pm window is the busiest, with 388 flights scheduled in it.
Across the year
Southwest on LAX to SJC through the year
June is the worst month at 66.7% on time, 23 points below January, the best at 89.7%. 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. August was the busiest month here, with 185 flights.
Across the week, Tuesday is the strongest day at 87.0% on time and Sunday the weakest at 72.7%, a spread of 14 points.
Arrival by arrival
How late Southwest on LAX to SJC runs when it is late
Southwest on LAX to SJC often beats the schedule: 551 of 1,854 completed flights, 30%, arrived 15 minutes or more early. The 359 late arrivals split 124 under half an hour, 138 between 30 and 60 minutes, and 97 an hour or more.
- 15+ min early551 flights29.7%
- Within 15 min944 flights50.9%
- 15–29 min late124 flights6.7%
- 30–59 min late138 flights7.4%
- 1–2 hours late76 flights4.1%
- 2+ hours late21 flights1.1%
Scale runs 0% to 100%.
Share of 1,854 completed flights by arrival against schedule.
A late pushback is often recovered here: of 527 departures that left 15 minutes late or more, 180 still arrived on time. Only 12 left on time and still arrived late.
The worst days
Worst days for Southwest on LAX to SJC
The latest arrival of the period was on 9 August 2026, 3 hours 23 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 9 August 2026 | 3 hours 23 minutes | Late-arriving aircraft |
| 7 March 2026 | 3 hours 11 minutes | Carrier |
| 22 June 2026 | 3 hours 9 minutes | Carrier |
| 23 August 2026 | 2 hours 48 minutes | Carrier |
| 27 July 2026 | 2 hours 42 minutes | Carrier |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 73% of the 18,000 delay minutes carriers reported here, and the remaining four split what is left.
- 73%Late-arriving aircraft
- 24%Carrier
- 3%National Airspace System
- 0%Security
73% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 18,000 reported delay minutes here, that single category outweighs weather by 73 to one. The split is drawn from 17,972 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 0.91% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
5.2% 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 about 50 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 76.8% on time across 1,867 flights, 4 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 4 points of difference.
The sample behind these figures is 1,871 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 LAX to SJC
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 89.7% on time and June 66.7%, a swing of 23 points. If the dates move at all, move them out of June before you think about anything else. 1,854 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to SJC, every carrier
- Southwest on SJC to LAX, the return leg
- SkyWest Airlines on LAX to SJC90.7%
- Delta Air Lines on LAX to SJC86.9%
- Frontier Airlines on LAX to SJC80.5%
- Southwest Airlines network-wide record
- Los Angeles International (LAX) delay statistics
- Norman Y. Mineta San Jose International (SJC) 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.