Carrier route record
WNORD→BNA
Southwest Airlines · Chicago to Nashville
- Flights
- 338
- Period
- July 2025 to June 2026
- Share of route
- 7%
- Carriers
- 9
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on ORD to BNA 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 77.6%. The late ones land about an hour behind schedule. That rests on 338 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 560 at 76.6% on time.
Republic Airways is the most reliable of the five carriers covered here at 76.6% on time across 560 flights.
Key figures
On time
70.7%
Arrivals under 15 minutes late, of 334 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
1.18%
National rate is 1.81%
Whole route
68.6%
Every carrier on ORD to BNA, 5,021 flights
These figures cover 338 flights between July 2025 and June 2026. Beyond the headline rate, 8.7% 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
Southwest against every carrier on ORD to BNA
Southwest flew 338 of the 5,021 flights on ORD to BNA, about 7% of it. Its 70.7% on time is 2 points better than the route as a whole, which runs 68.6%. Ranked by on-time rate it is number five of nine carriers on the route, where the range runs from PSA at 100.0% to SkyWest at 61.0%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Republic Airways arrives on time 76.6% of the time; SkyWest Airlines manages 61.0%. Sample sizes sit next to every figure, because a two-point gap across 1,467 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| PSA Airlinesthin sample | 3 | 100.0% | — | 0.00% | A+ |
| Republic Airways | 560 | 76.6% | 56 min | 1.43% | B |
| Envoy Air | 783 | 74.8% | 60 min | 3.19% | C− |
| Frontier Airlinesthin sample | 81 | 71.8% | 71 min | 3.70% | C− |
| Southwest Airlines (this page)thin sample | 338 | 70.7% | 60 min | 1.18% | C |
| United Airlines | 1,381 | 70.4% | 74 min | 1.67% | C |
| Spirit Airlinesthin sample | 26 | 69.2% | 32 min | 0.00% | C+ |
| American Airlines | 382 | 63.8% | 116 min | 1.83% | D |
| SkyWest Airlines | 1,467 | 61.0% | 89 min | 3.89% | D− |
SkyWest Airlines cancels 3.9% 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
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 12 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am—
- 11am–2pm99 flights78.4%
- 2pm–5pm213 flights66.5%
- 5pm–8pm26 flights—
- 8pm–5am—
Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 78.4% on time, ahead of 2pm–5pm at 66.5%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 2pm–5pm window is the busiest, with 213 flights scheduled in it.
Across the year
Southwest on ORD to BNA through the year
July is the worst month at 38.7% on time, 48 points below September, the best at 86.7%. 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 31 flights.
Across the week, Saturday is the strongest day at 76.6% on time and Thursday the weakest at 66.7%. 10 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 56% of the 5,862 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.
- 56%Late-arriving aircraft
- 25%National Airspace System
- 13%Carrier
- 6%Extreme weather
56% 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 5,862 reported delay minutes here, that single category outweighs weather by 9 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 5,862 reported delay minutes.
Cancellations sit at 1.18% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.7% 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 about an hour, which a normal layover absorbs.
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 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 76.7% on time across 338 flights, 6 points above 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 6 points of difference.
One caution: this is a thin sample. 338 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 ORD to BNA
Put together: treat all of this as provisional. 338 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 70.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 334 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to BNA, every carrier
- Southwest on BNA to ORD, the return leg
- Republic Airways on ORD to BNA76.6%
- Envoy Air on ORD to BNA74.8%
- United Airlines on ORD to BNA70.4%
- American Airlines on ORD to BNA63.8%
- SkyWest Airlines on ORD to BNA61.0%
- Southwest Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Nashville International (BNA) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.