Route reliability record
BNA→ORD
Nashville to Chicago
- Flights
- 5,034
- Period
- June 2025 to May 2026
- Distance
- 409 mi
- Carriers
- 9
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.4%. The late ones land an hour and a half behind schedule. That rests on 5,034 flights, of which Southwest Airlines flew 365 at 75.4% on time.
Southwest Airlines is the most reliable of the six carriers covered here at 75.4% on time across 365 flights.
Key figures
On time
70.0%
Arrivals under 15 minutes late, of 4,889 completed flights
Avg delay
93 min
Across delayed arrivals only, not all flights
Cancelled
2.60%
National rate is 1.80%
Best carrier
Southwest
75.4% on time across 365 flights
These figures cover 5,034 flights between June 2025 and May 2026. Beyond the headline rate, 13.2% 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 ORD
The choice of carrier is not cosmetic here. Southwest Airlines arrives on time 75.4% of the time; American Airlines manages 65.9%. Sample sizes sit next to every figure, because a two-point gap across 425 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 365 | 75.4% | 59 min | 1.37% | B |
| Republic Airways | 571 | 72.7% | 80 min | 2.10% | C |
| United Airlines | 1,345 | 72.2% | 91 min | 2.01% | C |
| Envoy Air | 748 | 71.0% | 75 min | 4.01% | C− |
| Spirit Airlinesthin sample | 36 | 66.7% | 108 min | 0.00% | C+ |
| SkyWest Airlines | 1,445 | 66.7% | 103 min | 3.11% | C− |
| PSA Airlinesthin sample | 3 | 66.7% | 30 min | 0.00% | C+ |
| American Airlines | 425 | 65.9% | 130 min | 2.12% | C |
| Frontier Airlinesthin sample | 96 | 61.3% | 87 min | 3.12% | D− |
Envoy Air cancels 4.0% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after 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 28 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,196 flights76.1%
- 8am–11am1,030 flights81.7%
- 11am–2pm769 flights78.1%
- 2pm–5pm1,077 flights59.2%
- 5pm–8pm913 flights54.1%
- 8pm–5am49 flights67.4%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 54.1% on time, against 81.7% for the 8am–11am 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.
Across the year
When delays peak on this route
This route's year swings by 24 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.
July is the worst month at 57.2% on time, 24 points below September, the best at 81.3%. 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.
Across the week, Saturday is the strongest day at 76.7% on time and Sunday the weakest at 64.9%. 12 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 137,000 reported delay minutes.
- 37%Carrier
- 29%Late-arriving aircraft
- 28%National Airspace System
- 6%Extreme weather
- 0%Security
The largest share of delay minutes, 37%, 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 51,000 of the 137,000 delay minutes reported here.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 81.7% on time here.
Cancellations run at 2.60%, against 1.80% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.2% of arrivals land a full hour or more behind schedule, against 8.2% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 409 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 8am–11am window matters as much as it does.
The return leg runs 68.7% on time across 5,031 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.
The sample behind these figures is 5,034 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 81.3% on time and July 57.2%, a swing of 24 points. If the dates move at all, move them out of July before you think about anything else.
Common questions
BNA to ORD questions
How often is BNA to ORD delayed?
Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 30.0% of the 5,034 flights in this analysis, against 22.6% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on BNA to ORD?
Southwest Airlines leads at 75.4% on time across 365 flights. American Airlines is at the other end on 65.9%, a gap of 10 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 ORD?
The 8am–11am departure window is the strongest at 81.7% on time. The 5pm–8pm window is the weakest at 54.1%, 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 July delays on BNA to ORD?
July is the weakest month at 57.2% on time, compared with 81.3% in September. Across the year that is 24 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
- ORD to BNA — the return legseparate record
- Nashville International (BNA) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- Southwest Airlines on-time record75.4%
- Republic Airways on-time record72.7%
- United Airlines on-time record72.2%
- What a cancellation rate actually tells you (and what it hides)
- The best time of day to fly, according to 7.05 million flight records
Direction matters. BNA to ORD and ORD 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, June 2025 to May 2026. Updated monthly. How this data is collected.