Nashville airport delays: how reliable is flying out of BNA?

A Nashville departure scheduled before 8am arrived on time 88.7% of the time over September 2025 to August 2026, level with the national figure of 89.3% for that window. A departure between 5pm and 8pm managed 62.3%, against 68.0% nationally. The 26.4-point gap between those two windows is among the widest of any large US airport, and at Nashville International the departure time is the decision that matters most. If I were booking out of BNA, I would pick the hour before I picked the airline.

Over the year, Nashville's departures ran 74.8% on time, below the national 77.3%, and ranked 49 of 60 airports with a page. The rest of the record is better than that headline. Cancellations were low at 1.50%, against 1.89% nationally, and late flights were short: an average of 63 minutes behind, against 73 nationally, with only 31.0% of late flights running an hour or more late.

Nashville is late often and late by a little.

All figures cover flights leaving Nashville, scored at their destination.

A Southwest airport

Southwest at Nashville flies more than half of all departures, far more than any other carrier, and Nashville is one of the places where Southwest passengers change planes. Southwest's record here sits just below the airport average, which it largely sets. Its network profile explains the rest of this guide: across all its flying, Southwest cancelled only 0.92% of flights and its late flights averaged 53 minutes, both among the best of any carrier, but its on-time rate falls more steeply through the day than almost any other airline's.

The network carriers fly in from their hubs and mostly beat the average. Delta at Nashville leads the chart by a clear margin, and American at Nashville and United at Nashville sit above the line. Republic at Nashville, flying regional jets to the Northeast, sits just below it.

The shape of a Southwest day

The curve is almost level for the first two windows, 88.7% and 86.1%, then falls away: 76.2% from 11am, 67.8% from 2pm and 62.3% from 5pm. After 8pm it stays down at 63.0%.

Southwest does not run banks. Its aircraft fly point to point, several legs a day, with short turns between them. An aircraft leaving Nashville at 7am has spent the night there and leaves on time. By 6pm the same aircraft may have been to Denver, Baltimore and Orlando, and any delay it picked up along the way is still with it, because a turn of well under an hour has little room to win time back. Late-arriving aircraft account for 47% of Nashville's delay minutes, against 40% nationally. The evening fade guide compares this pattern across all the airlines, and the departure time guide ranks Nashville among the airports where it matters most.

Delta's early departures show how good the morning can be. Its 6am to Minneapolis, DL 2221, its 6am to Detroit, DL 2439, and its 5:15am to Atlanta, DL 2637, were among the most punctual regular flights in the country.

Summer is long in Nashville

The worst month was July at 64.2%, and June at Nashville (65.5%) and May (70.6%) were not far behind. That is a three-month run of weak summer flying, earlier and longer than at most airports, as Southeast thunderstorms arrive in late spring and keep coming. A Southwest schedule turns an afternoon storm at Nashville, or at any airport its aircraft pass through, into an evening of late departures. Nationally, Memorial Day weekend 2026 ran 4.6 points worse than the weeks around it, and Nashville fell further than most airports.

The best month was September at 85.2%, and January was close behind at 84.3%. January's figure needs a caveat. Its cancellation rate was several times the airport's normal level, consistent with a winter storm that grounded flights across Tennessee. The flights that operated ran on time; many did not operate.

Weekdays

The best weekday was Wednesday at 80.0%, the worst Sunday at 70.0%. Nashville is a weekend destination, and its weekday pattern shows it: Thursday (72.5%), Friday (72.9%) and Monday (72.2%) are all weak, while Saturday (77.8%) holds up nearly as well as the midweek days.

Where the delay minutes come from

Nashville's air traffic share is below the national level at 19%, and its extreme-weather share is small at 3%. The delay minutes come from the rotation. Dallas Love Field and Houston Hobby, two other airports where Southwest flies most of the schedule, show a similarly heavy late-aircraft share. Atlanta, a few hours' drive away under the same summer weather, codes far more of its delay to the airline, partly a difference in how Delta records causes, as the Atlanta guide explains. Delta's hubs put more delay under "air carrier" and less under "late-arriving aircraft" than the national split, and its regional partner Endeavor Air never appears as a separate carrier at those hubs in this data; I read that as a reporting convention, not a finding about Delta's operation.

{
 "flights": 110118,
 "completed": 108168,
 "onTimePct": 74.8,
 "veryLatePct": 7.8,
 "avgDelayMin": 63.2,
 "medianArrDelay": -3,
 "cancelPct": 1.5,
 "divertPct": 0.27,
 "causes": {
  "carrier": 0.3114,
  "weather": 0.0291,
  "nas": 0.1892,
  "security": 0.0015,
  "lateAircraft": 0.4688
 },
 "byHourBlock": [88.7, 86.1, 76.2, 67.8, 62.3, 63 ],
 "byMonth": [84.3, 81, 75.1, 77.7, 70.6, 65.5, 64.2, 70.1, 85.2, 75.4, 79, 74.9 ],
 "byDow": [72.2, 79.7, 80, 72.5, 72.9, 77.8, 70 ]
}

This is the file my pipeline writes for Nashville each month; every figure in this guide is recomputed from it, and the build refuses to publish a guide that quotes a number it cannot recompute.

Best and worst routes

The weakest busy routes are to the Northeast and Chicago. Nashville to Boston ran 67.6% on time, with a wide carrier gap: Republic's flights well ahead of Southwest's. Nashville to O'Hare, the busiest route, ran 70.9%, Nashville to LaGuardia 70.7% and Nashville to Washington National 71.3%.

The best busy route is Nashville to Atlanta at 82.7%, where Delta's flights ran far ahead of Southwest's. Nashville to Austin, at 80.4%, is the best of the Southwest-heavy routes. On Nashville to Denver, United beat Southwest mainly because Southwest's evening departures on the route fell so far.

Connecting through Nashville

Southwest itineraries often connect here, and Southwest does not build its schedule around connection banks, so a connection is two independent flights that happen to share an airport. Inbound flights from Dallas-Fort Worth ran 67.1% and from O'Hare 69.2%; from Minneapolis 81.0%. Nashville's inbound record puts it in the riskier half of large airports for a one-hour connection. On a Southwest itinerary after midday, I would not book one that short here. The connection risk calculator runs your own inbound route.

What I would book out of Nashville

Take the first departure of the day. At Nashville it is worth more than at almost any other large airport, and it costs nothing but an early alarm.

On Southwest, connect before noon. An afternoon connection on a Southwest itinerary through BNA rides two aircraft that have both had a full day.

In May, June and July, avoid the evening entirely. Nashville's summer is long, and its evening departures take the full weight of it.

On Atlanta and Boston, compare carriers. On both routes the carrier gap is larger than the gap between morning and afternoon.

Explore Nashville: Nashville International (BNA) · Southwest at BNA · BNA in July · Baltimore/Washington guide · Best time to fly tool