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DelayAtlas

Carrier route record

WNATLBNA

Southwest Airlines · Atlanta to Nashville

Flights
881
Period
July 2025 to June 2026
Share of route
21%
Carriers
2
B+GRADE

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

Southwest on ATL to BNA lands a B+, 2 points 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 about an hour on average. That is a workable record, not a spotless one. That rests on 881 flights, with a median arrival 5 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on ATL 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

79.1%

Arrivals under 15 minutes late, of 877 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

0.45%

National rate is 1.81%

Whole route

81.4%

Every carrier on ATL to BNA, 4,242 flights

These figures cover 881 flights between July 2025 and June 2026. The median arrival is 5 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 ATL to BNA

Southwest flew 881 of the 4,242 flights on ATL to BNA, about 21% of it. Its 79.1% on time is 2 points worse than the route as a whole, which runs 81.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 82.0% to Southwest at 79.1%.

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 ATL to BNA
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines3,36182.0%56 min1.90%B
Southwest Airlines (this page)88179.1%65 min0.45%B+

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 28 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–8am67 flights95.5%
  • 8am–11am138 flights94.9%
  • 11am–2pm160 flights89.9%
  • 2pm–5pm195 flights71.1%
  • 5pm–8pm160 flights69.8%
  • 8pm–5am161 flights67.1%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 95.5% of the time, against 67.1% for the overnight window. That is 28 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 195 flights scheduled in it.

Across the year

Southwest on ATL to BNA through the year

On-time rate by calendar month89J87F75M86A73M62J73J88A91S72O82N77D
Darker means more delays. Figures are on-time percentages.September best, June worst

June is the worst month at 62.2% on time, 28 points below September, the best at 90.5%. 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. March was the busiest month here, with 83 flights.

Across the week, Wednesday is the strongest day at 88.6% on time and Thursday the weakest at 72.1%. 17 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.7Mon81.6Tue88.6Wed72.1Thu78.0Fri85.2Sat73.5Sun
Monday: 77.7 percent on time. Tuesday: 81.6 percent on time. Wednesday: 88.6 percent on time. Thursday: 72.1 percent on time. Friday: 78.0 percent on time. Saturday: 85.2 percent on time. Sunday: 73.5 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 12,000 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
    29%
  • National Airspace System
    17%
  • Extreme weather
    1%

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 12,000 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 11,885 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 95.5% on time here.

Cancellations are rare at 0.45%, 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

7.9% 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 about an hour, which a normal layover absorbs.

At 214 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 74.6% on time across 879 flights, 5 points below 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 5 points of difference.

One caution: this is a thin sample. 881 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Southwest on ATL to BNA

Put together: treat all of this as provisional. 881 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 79.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 877 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.