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DelayAtlas

Carrier route record

WNLASBNA

Southwest Airlines · Las Vegas to Nashville

Flights
1,781
Period
July 2025 to June 2026
Share of route
87%
Carriers
6
B+GRADE

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

Southwest on LAS to BNA lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That is a workable record, not a spotless one. That rests on 1,781 flights, with a median arrival 3 minutes early.

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

Key figures

On time

78.7%

Arrivals under 15 minutes late, of 1,767 completed flights

Avg delay

44 min

Across delayed arrivals only, not all flights

Cancelled

0.62%

National rate is 1.81%

Whole route

79.0%

Every carrier on LAS to BNA, 2,040 flights

These figures cover 1,781 flights between July 2025 and June 2026. The median arrival is 3 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 BNA

Southwest flew 1,781 of the 2,040 flights on LAS to BNA, most of the route. Its 78.7% on time is about level with the route as a whole at 79.0%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from American at 100.0% to Allegiant at 50.0%. Five 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 BNA
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlinesthin sample2100.0%0.00%A+
Spirit Airlinesthin sample24182.1%73 min2.49%B
Southwest Airlines (this page)1,78178.7%44 min0.62%B+
Frontier Airlinesthin sample1266.7%27 min0.00%C+
Delta Air Linesthin sample250.0%95 min0.00%F+
Allegiant Airthin sample250.0%60 min0.00%F+

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 37 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–8am427 flights94.8%
  • 8am–11am277 flights81.0%
  • 11am–2pm273 flights62.6%
  • 2pm–5pm156 flights57.8%
  • 5pm–8pm254 flights67.5%
  • 8pm–5am394 flights86.2%

Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 94.8% of the time, against 57.8% for the afternoon window. That is 37 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 427 flights scheduled in it.

Across the year

Southwest on LAS to BNA through the year

On-time rate by calendar month86J83F75M79A67M66J80J83A83S77O83N88D
Darker means more delays. Figures are on-time percentages.December best, June worst

June is the worst month at 65.9% on time, 22 points below December, 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. June was the busiest month here, with 173 flights.

Across the week, Saturday is the strongest day at 86.0% on time and Friday the weakest at 72.9%. 13 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.9Mon83.0Tue81.4Wed74.3Thu72.9Fri86.0Sat76.5Sun
Monday: 77.9 percent on time. Tuesday: 83.0 percent on time. Wednesday: 81.4 percent on time. Thursday: 74.3 percent on time. Friday: 72.9 percent on time. Saturday: 86.0 percent on time. Sunday: 76.5 percent on time

Delay causes

Why Southwest runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 16,000 reported delay minutes.

  • Late-arriving aircraft
    41%
  • Carrier
    39%
  • National Airspace System
    17%
  • Extreme weather
    3%
  • Security
    0%

41% 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 16,000 reported delay minutes here, that single category outweighs weather by 13 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 16,390 reported delay minutes.

The largest share of delay minutes, 39%, 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 6,463 of the 16,000 delay minutes reported here.

Cancellations are rare at 0.62%, 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

Badly late arrivals are rare here: only 4.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 1,587 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg runs 76.7% on time across 1,760 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 1,781 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 BNA

Put together: the calendar is the biggest lever here, not the carrier or the hour. December runs 87.8% on time and June 65.9%, a swing of 22 points. If the dates move at all, move them out of June before you think about anything else. 1,767 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.