Carrier route record
WNBNA→MIA
Southwest Airlines · Nashville to Miami
- Flights
- 735
- Period
- July 2025 to June 2026
- Share of route
- 29%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BNA to MIA 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 735 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.6%, so Southwest on BNA to MIA runs 5 points behind the country as a whole. Across a thousand flights that is about 50 extra late arrivals.
Key figures
On time
72.6%
Arrivals under 15 minutes late, of 725 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
Whole route
75.1%
Every carrier on BNA to MIA, 2,504 flights
These figures cover 735 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Southwest against every carrier on BNA to MIA
Southwest flew 735 of the 2,504 flights on BNA to MIA, about 29% of it. Its 72.6% on time is 3 points worse than the route as a whole, which runs 75.1%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 77.3% to Spirit at 69.8%. 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 1,321 | 77.3% | 91 min | 1.29% | B |
| Envoy Airthin sample | 346 | 73.2% | 68 min | 1.45% | C |
| Southwest Airlines (this page) | 735 | 72.6% | 52 min | 1.09% | C |
| Republic Airwaysthin sample | 37 | 72.2% | 71 min | 2.70% | C |
| Spirit Airlinesthin sample | 65 | 69.8% | 71 min | 3.08% | 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 30 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–8am78 flights89.7%
- 8am–11am147 flights87.5%
- 11am–2pm132 flights70.2%
- 2pm–5pm72 flights76.5%
- 5pm–8pm256 flights60.2%
- 8pm–5am50 flights66.0%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 60.2% on time, against 89.7% 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 5pm–8pm window is the busiest, with 256 flights scheduled in it.
Across the year
Southwest on BNA to MIA through the year
June is the worst month at 48.3% on time, 41 points below September, the best at 89.3%. 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. May was the busiest month here, with 72 flights.
Across the week, Tuesday is the strongest day at 81.2% on time and Friday the weakest at 64.3%. 17 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 59% of the 10,000 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.
- 59%Late-arriving aircraft
- 27%Carrier
- 13%National Airspace System
- 1%Extreme weather
59% 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 10,000 reported delay minutes here, that single category outweighs weather by 47 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 10,315 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 89.7% on time here.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.27%.
Connections and stage length
What a delay here costs
7.7% 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 806 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 71.2% on time across 735 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 735 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 BNA to MIA
Put together: treat all of this as provisional. 735 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 72.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 725 completed flights over 12 months sit behind that.
Related
Where to go next
- BNA to MIA, every carrier
- Southwest on MIA to BNA, the return leg
- American Airlines on BNA to MIA77.3%
- Envoy Air on BNA to MIA73.2%
- Southwest Airlines network-wide record
- Nashville International (BNA) delay statistics
- Miami International (MIA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.