Carrier route record
WNBNA→ORD
Southwest Airlines · Nashville to Chicago
- 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 BNA to ORD lands a B, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 338 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 562 at 73.4% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on BNA to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.7%
Arrivals under 15 minutes late, of 331 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
1.48%
National rate is 1.81%
Whole route
70.4%
Every carrier on BNA to ORD, 5,024 flights
These figures cover 338 flights between July 2025 and June 2026. The median arrival is 4 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
Southwest against every carrier on BNA to ORD
Southwest flew 338 of the 5,024 flights on BNA to ORD, about 7% of it. Its 76.7% on time is 6 points better than the route as a whole, which runs 70.4%. Ranked by on-time rate it is first of nine carriers on the route, where the range runs from Southwest at 76.7% to American at 65.5%. 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 73.4% of the time; American Airlines manages 65.5%. Sample sizes sit next to every figure, because a two-point gap across 384 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines (this page)thin sample | 338 | 76.7% | 59 min | 1.48% | B |
| Republic Airways | 562 | 73.4% | 80 min | 2.14% | C |
| Envoy Air | 782 | 73.0% | 75 min | 3.84% | C− |
| United Airlines | 1,380 | 72.3% | 93 min | 2.10% | C |
| Frontier Airlinesthin sample | 81 | 67.9% | 82 min | 3.70% | C− |
| Spirit Airlinesthin sample | 27 | 66.7% | 45 min | 0.00% | C+ |
| PSA Airlinesthin sample | 3 | 66.7% | 30 min | 0.00% | C+ |
| SkyWest Airlines | 1,467 | 65.9% | 102 min | 3.68% | C− |
| American Airlines | 384 | 65.5% | 120 min | 1.82% | C |
Envoy Air cancels 3.8% 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 29 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am147 flights88.8%
- 11am–2pm120 flights72.3%
- 2pm–5pm71 flights59.4%
- 5pm–8pm—
- 8pm–5am—
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 88.8% of the time, against 59.4% for the afternoon window. That is 29 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 147 flights scheduled in it.
Across the year
Southwest on BNA to ORD through the year
- Jul–Sep 202592 flights72.2%
- Oct–Dec 202592 flights82.2%
- Jan–Mar 202690 flights80.5%
- Apr–Jun 202664 flights70.3%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 76.7% on time across 338 flights.
Southwest on BNA to ORD did not run the same all year. Its best quarter was Oct–Dec 2025 at 82.2% on time and its weakest Apr–Jun 2026 at 70.3%, a swing of 12 points on roughly 85 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Tuesday is the strongest day at 87.8% on time and Monday the weakest at 66.0%. 22 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. National Airspace System accounts for 51% of the 4,547 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.
- 51%National Airspace System
- 27%Late-arriving aircraft
- 22%Carrier
- 1%Extreme weather
51% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,317 minutes out of 4,547, against a national NAS share of 21%. The split is drawn from 4,547 reported delay minutes.
Cancellations sit at 1.48% against a national 1.81%, which is ordinary. Diversions add another 0.59%.
Connections and stage length
What a delay here costs
6.9% 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 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 70.7% on time across 338 flights, 6 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 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 BNA to ORD
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 76.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 331 completed flights over 12 months sit behind that.
Related
Where to go next
- BNA to ORD, every carrier
- Southwest on ORD to BNA, the return leg
- Republic Airways on BNA to ORD73.4%
- Envoy Air on BNA to ORD73.0%
- United Airlines on BNA to ORD72.3%
- SkyWest Airlines on BNA to ORD65.9%
- American Airlines on BNA to ORD65.5%
- Southwest Airlines network-wide record
- Nashville International (BNA) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- How to read this site: grades, sample sizes, and honest caveats
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.