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DelayAtlas

Carrier route record

WNLASLAX

Southwest Airlines · Las Vegas to Los Angeles

Flights
2,386
Period
July 2025 to June 2026
Share of route
29%
Carriers
8
C+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on LAS to LAX sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land roughly 45 minutes behind schedule. That rests on 2,386 flights. The strongest carrier on the route with a full sample, Spirit Airlines, flew 646 at 87.3% on time.

Spirit Airlines is the most reliable of the five carriers covered here at 87.3% on time across 646 flights.

Key figures

On time

68.2%

Arrivals under 15 minutes late, of 2,377 completed flights

Avg delay

47 min

Across delayed arrivals only, not all flights

Cancelled

0.38%

National rate is 1.81%

Whole route

78.8%

Every carrier on LAS to LAX, 8,325 flights

These figures cover 2,386 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Southwest against every carrier on LAS to LAX

Southwest flew 2,386 of the 8,325 flights on LAS to LAX, about 29% of it. Its 68.2% on time is 11 points worse than the route as a whole, which runs 78.8%. Ranked by on-time rate it is last of eight carriers on the route, where the range runs from Spirit at 87.3% to Southwest at 68.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Spirit Airlines arrives on time 87.3% of the time; American Airlines manages 75.3%. Sample sizes sit next to every figure, because a two-point gap across 1,060 flights means less than a ten-point one.

On-time performance by carrier on LAS to LAX
AirlineFlightsOn timeAvg delayCancelledGrade
Spirit Airlines64687.3%62 min0.93%A+
United Airlines1,57486.2%55 min0.70%A+
SkyWest Airlinesthin sample31284.0%66 min1.60%B
Delta Air Lines1,73784.0%72 min0.92%B+
Frontier Airlines59380.6%57 min0.17%B+
American Airlines1,06075.3%93 min0.94%B+
Alaska Airlinesthin sample1770.6%30 min0.00%C+
Southwest Airlines (this page)2,38668.2%47 min0.38%C+

The spread between Spirit and American is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.

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

  • 5am–8am297 flights90.2%
  • 8am–11am484 flights82.0%
  • 11am–2pm372 flights70.7%
  • 2pm–5pm399 flights57.4%
  • 5pm–8pm383 flights55.6%
  • 8pm–5am451 flights57.0%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 55.6% on time, against 90.2% 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 484 flights scheduled in it.

Across the year

Southwest on LAS to LAX through the year

On-time rate by calendar month72J77F73M70A61M63J59J74A66S66O68N72D
Darker means more delays. Figures are on-time percentages.February best, July worst

July is the worst month at 58.9% on time, 19 points below February, the best at 77.4%. 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 219 flights.

Across the week, Saturday is the strongest day at 80.6% on time and Sunday the weakest at 59.0%. 22 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week61.1Mon73.9Tue75.4Wed71.4Thu62.1Fri80.6Sat59.0Sun
Monday: 61.1 percent on time. Tuesday: 73.9 percent on time. Wednesday: 75.4 percent on time. Thursday: 71.4 percent on time. Friday: 62.1 percent on time. Saturday: 80.6 percent on time. Sunday: 59.0 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 53% of the 35,000 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
    53%
  • Carrier
    35%
  • National Airspace System
    11%
  • Extreme weather
    0%
  • Security
    0%

53% 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 35,000 reported delay minutes here, that single category outweighs weather by 53 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 35,491 reported delay minutes.

The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 13,000 of the 35,000 delay minutes reported here.

Cancellations are rare at 0.38%, 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

6.6% 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 236 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 72.2% on time across 2,386 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 2,386 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 LAX

Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 77.4% on time and July 58.9%, a swing of 19 points. If the dates move at all, move them out of July before you think about anything else. 2,377 completed flights over 12 months sit behind that.

Related

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.