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DelayAtlas

Carrier route record

WNBNADCA

Southwest Airlines · Nashville to Washington

Flights
1,653
Period
July 2025 to June 2026
Share of route
38%
Carriers
5
CGRADE

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

Southwest on BNA to DCA sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 1,653 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 1,861 at 75.1% on time.

The national on-time rate over the same period is 77.6%, so Southwest on BNA to DCA runs 5 points behind the country as a whole. Across a thousand flights that is about 54 extra late arrivals.

Key figures

On time

72.2%

Arrivals under 15 minutes late, of 1,623 completed flights

Avg delay

52 min

Across delayed arrivals only, not all flights

Cancelled

1.45%

National rate is 1.81%

Whole route

73.3%

Every carrier on BNA to DCA, 4,330 flights

These figures cover 1,653 flights between July 2025 and June 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Southwest against every carrier on BNA to DCA

Southwest flew 1,653 of the 4,330 flights on BNA to DCA, about 38% of it. Its 72.2% on time is about level with the route as a whole at 73.3%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from American at 78.4% to PSA at 65.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Republic Airways arrives on time 75.1% of the time; PSA Airlines manages 65.1%. Sample sizes sit next to every figure, because a two-point gap across 387 flights means less than a ten-point one.

On-time performance by carrier on BNA to DCA
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlinesthin sample31378.4%65 min5.43%B−
Republic Airways1,86175.1%62 min2.90%B
Envoy Airthin sample11673.6%60 min5.17%C−
Southwest Airlines (this page)1,65372.2%52 min1.45%C
PSA Airlines38765.1%117 min10.08%C−

PSA Airlines cancels 10.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 24 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am242 flights83.9%
  • 8am–11am344 flights85.5%
  • 11am–2pm368 flights70.0%
  • 2pm–5pm332 flights63.2%
  • 5pm–8pm127 flights61.3%
  • 8pm–5am240 flights62.8%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 61.3% on time, against 85.5% for the 8am–11am 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 11am–2pm window is the busiest, with 368 flights scheduled in it.

Across the year

Southwest on BNA to DCA through the year

On-time rate by calendar month84J72F63M79A66M56J67J80A82S76O70N75D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 56.1% on time, 28 points below January, the best at 84.4%. 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. October was the busiest month here, with 153 flights.

Across the week, Saturday is the strongest day at 82.6% on time and Friday the weakest at 66.0%. 17 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week67.5Mon77.0Tue77.0Wed68.6Thu66.0Fri82.6Sat69.6Sun
Monday: 67.5 percent on time. Tuesday: 77.0 percent on time. Wednesday: 77.0 percent on time. Thursday: 68.6 percent on time. Friday: 66.0 percent on time. Saturday: 82.6 percent on time. Sunday: 69.6 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 23,000 reported delay minutes.

  • Late-arriving aircraft
    39%
  • National Airspace System
    35%
  • Carrier
    25%
  • Extreme weather
    1%
  • Security
    0%

39% 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 23,000 reported delay minutes here, that single category outweighs weather by 28 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 23,337 reported delay minutes.

35% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 8,142 minutes out of 23,000, against a national NAS share of 21%.

Cancellations sit at 1.45% against a national 1.81%, which is ordinary. Diversions add another 0.36%.

Connections and stage length

What a delay here costs

8.0% 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 562 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 is a different operation and performs like one: it runs 75.9% on time across 1,653 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 1,653 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 BNA to DCA

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 84.4% on time and June 56.1%, a swing of 28 points. If the dates move at all, move them out of June before you think about anything else. 1,623 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.