Carrier route record
WNBNA→SLC
Southwest Airlines · Nashville to Salt Lake City
- Flights
- 272
- Period
- September 2025 to August 2026
- Share of route
- 23%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BNA to SLC sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land about 50 minutes behind schedule. That rests on 272 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on BNA to SLC runs 6 points behind the country as a whole. Across a thousand flights that is about 62 extra late arrivals.
Key figures
On time
71.1%
Arrivals under 15 minutes late, of 270 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.74%
National rate is 1.89%
Whole route
83.5%
Every carrier on BNA to SLC, 1,205 flights
These figures cover 272 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Southwest against every carrier on BNA to SLC
Southwest flew 272 of the 1,205 flights on BNA to SLC, about 23% of it. Its 71.1% on time is 12 points worse than the route as a whole, which runs 83.5%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 87.1% to Southwest at 71.1%.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 933 | 87.1% | 61 min | 0.64% | A+ |
| Southwest Airlines (this page)thin sample | 272 | 71.1% | 50 min | 0.74% | C+ |
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Departure window
When Southwest runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 272 flights.
- 5am–8am—
- 8am–11am9 flights—
- 11am–2pm151 flights73.2%
- 2pm–5pm96 flights63.5%
- 5pm–8pm11 flights—
- 8pm–5am5 flights—
Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 73.2% on time, ahead of 2pm–5pm at 63.5%. 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 11am–2pm window is the busiest, with 151 flights scheduled in it.
Across the year
Southwest on BNA to SLC through the year
- Jul–Sep 202530 flights83.3%
- Oct–Dec 202592 flights79.3%
- Jan–Mar 202650 flights85.4%
- Apr–Jun 202638 flights42.1%
- Jul–Sep 202662 flights59.7%
Scale runs 35% to 90%.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 71.1% on time across 272 flights.
Southwest on BNA to SLC did not run the same all year. Its best quarter was Jan–Mar 2026 at 85.4% on time and its weakest Apr–Jun 2026 at 42.1%, a swing of 43 points on roughly 54 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, Friday is the strongest day at 77.8% on time and Saturday the weakest at 64.4%, a spread of 13 points.
Arrival by arrival
How late Southwest on BNA to SLC runs when it is late
The 78 late arrivals split 29 under half an hour, 32 between 30 and 60 minutes, and 17 an hour or more.
- 15+ min early32 flights11.9%
- Within 15 min160 flights59.3%
- 15–29 min late29 flights10.7%
- 30–59 min late32 flights11.9%
- 1–2 hours late13 flights4.8%
- 2+ hours late4 flights1.5%
Scale runs 0% to 100%.
Share of 270 completed flights by arrival against schedule.
A late pushback is often recovered here: of 102 departures that left 15 minutes late or more, 31 still arrived on time. 7 flights left on time and still arrived late.
The worst days
Worst days for Southwest on BNA to SLC
The latest arrival of the period was on 28 August 2026, 3 hours 50 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 August 2026 | 3 hours 50 minutes | Late-arriving aircraft |
| 27 June 2026 | 3 hours 25 minutes | Late-arriving aircraft |
| 10 October 2025 | 3 hours 18 minutes | Carrier |
| 2 May 2026 | 2 hours 38 minutes | Late-arriving aircraft |
| 10 November 2025 | 1 hour 50 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 56% of the 3,897 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Late-arriving aircraft
- 30%Carrier
- 11%National Airspace System
- 3%Extreme weather
56% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,897 reported delay minutes here, that single category outweighs weather by 19 to one. The split is drawn from 3,897 reported delay minutes.
Cancellations are rare at 0.74%, below the national 1.89% 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 costs
6.3% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 50 minutes, which a normal layover absorbs.
The 1,404 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.
The return leg is a different operation and performs like one: it runs 85.2% on time across 272 flights, 14 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 14 points of difference.
One caution: this is a thin sample. 272 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 SLC
Put together: treat all of this as provisional. 272 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 71.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 270 completed flights over 12 months sit behind that.
Related
Where to go next
- BNA to SLC, every carrier
- Southwest on SLC to BNA, the return leg
- Delta Air Lines on BNA to SLC87.1%
- Southwest Airlines network-wide record
- Nashville International (BNA) delay statistics
- Salt Lake City International (SLC) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.