Route reliability record

BNA→MIA

Nashville to Miami

Flights: 2,504
Period: July 2025 to June 2026
Distance: 806 mi
Carriers: 5

This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 2,504 flights, of which American Airlines flew 1,321 at 77.3% on time.

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

On time

75.1%

Arrivals under 15 minutes late, of 2,462 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

1.32%

National rate is 1.81%

Best carrier

American

77.3% on time across 1,321 flights

These figures cover 2,504 flights between July 2025 and June 2026. Beyond the headline rate, 8.6% 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

Which airline is most reliable on BNA to MIA

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on BNA to MIA
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	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−

No carrier stands out. American tops the table at 77.3%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am819 flights86.2%
8am–11am268 flights86.0%
11am–2pm427 flights70.9%
2pm–5pm191 flights70.1%
5pm–8pm749 flights63.3%
8pm–5am50 flights66.0%

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

The 5pm–8pm window is where this operation falls apart: 63.3% on time, against 86.2% 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 5am–8am window is the busiest, with 819 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 22 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.September best, July worst

July is the worst month at 61.8% on time, 22 points below September, the best at 83.7%. 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. January was the busiest month here, with 241 flights.

Across the week, Wednesday is the strongest day at 82.5% on time and Sunday the weakest at 65.4%. 17 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 45,000 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
55%
Carrier
31%
National Airspace System
12%
Extreme weather
2%
Security
0%

55% 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 45,000 reported delay minutes here, that single category outweighs weather by 32 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 45,129 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 86.2% on time here.

Cancellations sit at 1.32% against a national 1.81%, which is ordinary. Diversions add another 0.36%.

Connections and stage length

What a delay here actually costs

8.6% 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 are the a little over an hour kind, 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 is a different operation and performs like one: it runs 71.4% on time across 2,503 flights, 4 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 4 points of difference.

The sample behind these figures is 2,504 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 this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 83.7% on time and July 61.8%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 2,462 completed flights over 12 months sit behind that.

Common questions

BNA to MIA questions

How often is BNA to MIA delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.9% of the 2,504 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on BNA to MIA?

American Airlines leads at 77.3% on time across 1,321 flights. Southwest Airlines is at the other end on 72.6%, a gap of 5 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on BNA to MIA?

The 5am–8am departure window is the strongest at 86.2% on time. The 5pm–8pm window is the weakest at 63.3%, 23 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are July delays on BNA to MIA?

July is the weakest month at 61.8% on time, compared with 83.7% in September. Across the year that is 22 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. BNA to MIA and MIA to BNA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures