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DelayAtlas

Carrier route record

WNAUSLAS

Southwest Airlines · Austin to Las Vegas

Flights
2,177
Period
July 2025 to June 2026
Share of route
76%
Carriers
5
B+GRADE

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

Southwest on AUS to LAS sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 2,177 flights, with a median arrival 2 minutes early.

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

Key figures

On time

75.1%

Arrivals under 15 minutes late, of 2,164 completed flights

Avg delay

49 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.81%

Whole route

73.8%

Every carrier on AUS to LAS, 2,866 flights

These figures cover 2,177 flights between July 2025 and June 2026. The median arrival is 2 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 AUS to LAS

Southwest flew 2,177 of the 2,866 flights on AUS to LAS, most of the route. Its 75.1% on time is about level with the route as a whole at 73.8%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from Allegiant at 85.0% to Frontier at 67.9%. Three 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 AUS to LAS
AirlineFlightsOn timeAvg delayCancelledGrade
Allegiant Airthin sample2085.0%86 min0.00%A+
Southwest Airlines (this page)2,17775.1%49 min0.32%B+
Delta Air Lines36570.2%85 min0.82%C+
Spirit Airlinesthin sample1369.2%40 min0.00%C+
Frontier Airlinesthin sample29167.9%74 min1.37%C

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 42 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–8am386 flights97.9%
  • 8am–11am314 flights93.9%
  • 11am–2pm373 flights77.3%
  • 2pm–5pm438 flights65.4%
  • 5pm–8pm342 flights60.3%
  • 8pm–5am324 flights55.9%

Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 55.9% on time, against 97.9% 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 438 flights scheduled in it.

Across the year

Southwest on AUS to LAS through the year

On-time rate by calendar month84J82F79M75A74M56J72J79A75S72O76N81D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 55.9% on time, 28 points below January, the best at 84.2%. 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. December was the busiest month here, with 201 flights.

Across the week, Saturday is the strongest day at 82.6% on time and Monday the weakest at 68.5%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week68.5Mon81.6Tue82.3Wed71.6Thu72.9Fri82.6Sat71.0Sun
Monday: 68.5 percent on time. Tuesday: 81.6 percent on time. Wednesday: 82.3 percent on time. Thursday: 71.6 percent on time. Friday: 72.9 percent on time. Saturday: 82.6 percent on time. Sunday: 71.0 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 58% of the 26,000 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
    58%
  • Carrier
    25%
  • National Airspace System
    16%
  • Extreme weather
    2%
  • Security
    0%

58% 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 26,000 reported delay minutes here, that single category outweighs weather by 29 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 26,119 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 97.9% on time here.

Cancellations are rare at 0.32%, 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.

The 1,090 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 73.3% on time across 2,176 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 2,177 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 AUS to LAS

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 84.2% on time and June 55.9%, a swing of 28 points. If the dates move at all, move them out of June before you think about anything else. 2,164 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.