Route reliability record
SJC→LAS
San Jose to Las Vegas
- Flights
- 3,829
- Period
- July 2025 to June 2026
- Distance
- 386 mi
- Carriers
- 5
This route lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 3,829 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 this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.7%
Arrivals under 15 minutes late, of 3,806 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.52%
National rate is 1.81%
Best carrier
Southwest
79.6% on time across 3,241 flights
These figures cover 3,829 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
Which airline is most reliable on SJC to LAS
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| Spirit Airlinesthin sample | 199 | 86.8% | 82 min | 0.50% | A+ |
| SkyWest Airlinesthin sample | 202 | 80.2% | 79 min | 0.00% | B+ |
| Southwest Airlines | 3,241 | 79.6% | 55 min | 0.46% | B+ |
| Frontier Airlinesthin sample | 185 | 72.4% | 62 min | 2.16% | C |
Departure window
The best time of day to leave
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–8am593 flights97.0%
- 8am–11am694 flights92.5%
- 11am–2pm667 flights79.6%
- 2pm–5pm877 flights71.2%
- 5pm–8pm523 flights71.1%
- 8pm–5am475 flights64.5%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 64.5% on time, against 97.0% 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 877 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 14 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 74.1% on time, 14 points below January, the best at 87.8%. 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 381 flights.
Across the week, Saturday is the strongest day at 87.6% on time and Thursday the weakest at 71.8%. 16 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 45,000 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.
- 51%Late-arriving aircraft
- 25%National Airspace System
- 21%Carrier
- 3%Extreme weather
- 0%Security
51% 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 45,000 reported delay minutes here, that single category outweighs weather by 16 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 44,701 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 97.0% on time here.
Cancellations are rare at 0.52%, 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 actually costs
6.7% 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 are the about an hour kind, 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 78.3% on time across 3,844 flights, within about a point 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 3,829 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 87.8% on time and July 74.1%, a swing of 14 points. If the dates move at all, move them out of July before you think about anything else. 3,806 completed flights over 12 months sit behind that.
Common questions
SJC to LAS questions
How often is SJC to LAS delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.3% of the 3,829 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is SJC to LAS compared with the rest of the country?
79.7% of flights arrive on time here against a national 77.6%, a difference of 2 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on SJC to LAS?
The 5am–8am departure window is the strongest at 97.0% on time. The 8pm–5am window is the weakest at 64.5%, 33 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on SJC to LAS?
July is the weakest month at 74.1% on time, compared with 87.8% in January. Across the year that is 14 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- LAS to SJC — the return legseparate record
- Norman Y. Mineta San Jose International (SJC) delay statistics
- Harry Reid International (LAS) delay statistics
- United Airlines on-time record100.0%
- Spirit Airlines on-time record86.8%
- SkyWest Airlines on-time record80.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SJC to LAS and LAS to SJC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.