Route reliability record
BNA→DEN
Nashville to Denver
- Flights
- 3,665
- Period
- July 2025 to June 2026
- Distance
- 1,013 mi
- Carriers
- 3
This route sits in the middle of the pack with a C+. 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 about an hour behind schedule. That rests on 3,665 flights, of which United Airlines flew 1,168 at 79.3% 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.
Key figures
On time
74.9%
Arrivals under 15 minutes late, of 3,631 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
National rate is 1.81%
Best carrier
United
79.3% on time across 1,168 flights
These figures cover 3,665 flights between July 2025 and June 2026. Beyond the headline rate, 8.2% 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 DEN
The choice of carrier is not cosmetic here. United Airlines arrives on time 79.3% of the time; Southwest Airlines manages 72.3%. Sample sizes sit next to every figure, because a two-point gap across 2,148 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,168 | 79.3% | 77 min | 0.77% | B+ |
| Frontier Airlinesthin sample | 349 | 76.1% | 87 min | 1.43% | B |
| Southwest Airlines | 2,148 | 72.3% | 51 min | 0.42% | C+ |
United leads Southwest by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 35 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am789 flights92.2%
- 8am–11am654 flights86.3%
- 11am–2pm347 flights73.4%
- 2pm–5pm826 flights67.3%
- 5pm–8pm713 flights57.5%
- 8pm–5am336 flights68.6%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 57.5% on time, against 92.2% 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 2pm–5pm window is the busiest, with 826 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 27 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.
June is the worst month at 58.9% on time, 27 points below November, the best at 85.8%. 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. July was the busiest month here, with 372 flights.
Across the week, Saturday is the strongest day at 79.3% on time and Thursday the weakest at 70.9%. 8 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 56,000 reported delay minutes.
- 38%Late-arriving aircraft
- 30%National Airspace System
- 29%Carrier
- 3%Extreme weather
- 0%Security
38% 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 56,000 reported delay minutes here, that single category outweighs weather by 14 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 55,736 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 92.2% on time here.
Cancellations are rare at 0.63%, 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 actually costs
8.2% 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 about an hour kind, which a normal layover absorbs.
The 1,013 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 74.3% on time across 3,658 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 3,665 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. November runs 85.8% on time and June 58.9%, a swing of 27 points. If the dates move at all, move them out of June before you think about anything else. 3,631 completed flights over 12 months sit behind that.
Common questions
BNA to DEN questions
How often is BNA to DEN 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 25.1% of the 3,665 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on BNA to DEN?
United Airlines leads at 79.3% on time across 1,168 flights. Southwest Airlines is at the other end on 72.3%, a gap of 7 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 DEN?
The 5am–8am departure window is the strongest at 92.2% on time. The 5pm–8pm window is the weakest at 57.5%, 35 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 June delays on BNA to DEN?
June is the weakest month at 58.9% on time, compared with 85.8% in November. Across the year that is 27 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DEN to BNA — the return legseparate record
- Nashville International (BNA) delay statistics
- Denver International (DEN) delay statistics
- United Airlines on-time record79.3%
- Frontier Airlines on-time record76.1%
- Southwest Airlines on-time record72.3%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BNA to DEN and DEN 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.