Carrier route record

WNLAS→SJC

Southwest Airlines · Las Vegas to San Jose

Flights: 3,255
Period: July 2025 to June 2026
Share of route: 85%
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 SJC lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 3,255 flights, with a median arrival 6 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on LAS to SJC from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

77.9%

Arrivals under 15 minutes late, of 3,244 completed flights

Avg delay

52 min

Across delayed arrivals only, not all flights

Cancelled

0.34%

National rate is 1.81%

Whole route

78.3%

Every carrier on LAS to SJC, 3,844 flights

These figures cover 3,255 flights between July 2025 and June 2026. The median arrival is 6 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 LAS to SJC

Southwest flew 3,255 of the 3,844 flights on LAS to SJC, most of the route. Its 77.9% on time is about level with the route as a whole at 78.3%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from United at 100.0% to Southwest at 77.9%. Four of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on LAS to SJC
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlinesthin sample	4	100.0%	—	0.00%	A+
Spirit Airlinesthin sample	198	81.2%	50 min	0.51%	B+
SkyWest Airlinesthin sample	202	81.2%	100 min	0.00%	B+
Frontier Airlinesthin sample	185	80.2%	63 min	1.62%	B
Southwest Airlines (this page)	3,255	77.9%	52 min	0.34%	B+

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 half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am552 flights97.1%
8am–11am499 flights88.3%
11am–2pm479 flights78.9%
2pm–5pm528 flights70.8%
5pm–8pm631 flights70.9%
8pm–5am566 flights63.4%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 63.4% on time, against 97.1% 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 5pm–8pm window is the busiest, with 631 flights scheduled in it.

Across the year

Southwest on LAS to SJC through the year

Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 68.6% on time, 20 points below January, the best at 88.3%. 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. May was the busiest month here, with 284 flights.

Across the week, Saturday is the strongest day at 87.6% on time and Sunday the weakest at 71.6%. 16 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 62% of the 37,000 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.

Late-arriving aircraft
62%
Carrier
33%
National Airspace System
5%
Extreme weather
0%
Security
0%

62% 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 37,000 reported delay minutes here, that single category outweighs weather by 62 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 36,996 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 97.1% on time here.

Cancellations are rare at 0.34%, 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

6.4% 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 50 minutes, which a normal layover absorbs.

At 386 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 79.6% on time across 3,241 flights, within 2 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 3,255 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 SJC

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 88.3% on time and June 68.6%, a swing of 20 points. If the dates move at all, move them out of June before you think about anything else. 3,244 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures