Route reliability record

DTW→BNA

Detroit to Nashville

Flights: 2,417
Period: July 2025 to June 2026
Distance: 456 mi
Carriers: 4

This route lands a B, about a point better than the national rate of 77.6%. About one flight in five arrive 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 2,417 flights, of which Delta Air Lines flew 1,403 at 79.5% 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

78.7%

Arrivals under 15 minutes late, of 2,378 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

National rate is 1.81%

Best carrier

Delta

79.5% on time across 1,403 flights

These figures cover 2,417 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

Which airline is most reliable on DTW to BNA

The two carriers here are closely matched: 2 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 DTW to BNA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,403	79.5%	61 min	1.85%	B
Spirit Airlinesthin sample	146	77.9%	73 min	0.68%	B+
Southwest Airlines	846	77.7%	39 min	0.71%	B+
SkyWest Airlinesthin sample	22	72.7%	56 min	0.00%	C+

No carrier stands out. Delta tops the table at 79.5%, 2 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 28 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am388 flights92.7%
8am–11am468 flights88.6%
11am–2pm472 flights84.3%
2pm–5pm506 flights66.7%
5pm–8pm219 flights64.7%
8pm–5am364 flights69.1%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 64.7% on time, against 92.7% 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 2pm–5pm window is the busiest, with 506 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 31 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.August best, December worst

December is the weak month at 59.5% on time, against 90.0% in August. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. October was the busiest month here, with 232 flights.

Across the week, Tuesday is the strongest day at 82.3% on time and Sunday the weakest at 75.3%. 7 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

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 27,000 reported delay minutes.

Carrier
39%
Late-arriving aircraft
35%
National Airspace System
24%
Extreme weather
2%
Security
0%

35% 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 27,000 reported delay minutes here, that single category outweighs weather by 15 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 27,127 reported delay minutes.

The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 11,000 of the 27,000 delay minutes reported here.

Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.25%.

Connections and stage length

What a delay here actually costs

5.8% 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 roughly 55 minutes kind, which a normal layover absorbs.

At 456 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 runs 79.1% on time across 2,420 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 2,417 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. August runs 90.0% on time and December 59.5%, a swing of 31 points. If the dates move at all, move them out of December before you think about anything else. 2,378 completed flights over 12 months sit behind that.

Common questions

DTW to BNA questions

How often is DTW to BNA delayed?

About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.3% of the 2,417 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 55 minutes on average.

Which airline is most reliable on DTW to BNA?

Delta Air Lines leads at 79.5% on time across 1,403 flights. Southwest Airlines is at the other end on 77.7%, a gap of 2 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 DTW to BNA?

The 5am–8am departure window is the strongest at 92.7% on time. The 5pm–8pm window is the weakest at 64.7%, 28 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 December delays on DTW to BNA?

December is the weakest month at 59.5% on time, compared with 90.0% in August. Across the year that is 31 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. DTW to BNA and BNA to DTW 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