Carrier route record
WNSLC→BNA
Southwest Airlines · Salt Lake City to Nashville
- 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 SLC to BNA earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 40 minutes. That rests on 272 flights, with a median arrival 5 minutes early.
Set against the rest of the country, Southwest's SLC to BNA record is 8 points better than the US average of 77.3%. That gap is worth roughly 79 fewer late arrivals for every thousand flights.
Key figures
On time
85.2%
Arrivals under 15 minutes late, of 270 completed flights
Avg delay
41 min
Across delayed arrivals only, not all flights
Cancelled
0.74%
National rate is 1.89%
Whole route
85.0%
Every carrier on SLC to BNA, 1,205 flights
These figures cover 272 flights between September 2025 and August 2026. The median arrival is 5 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.
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Carrier by carrier
Southwest against every carrier on SLC to BNA
Southwest flew 272 of the 1,205 flights on SLC to BNA, about 23% of it. Its 85.2% on time is about level with the route as a whole at 85.0%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Southwest at 85.2% to Delta at 85.0%.
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 |
|---|---|---|---|---|---|
| Southwest Airlines (this page)thin sample | 272 | 85.2% | 41 min | 0.74% | A+ |
| Delta Air Lines | 933 | 85.0% | 55 min | 0.54% | A+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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–8am14 flights—
- 8am–11am48 flights87.2%
- 11am–2pm199 flights84.8%
- 2pm–5pm11 flights—
- 5pm–8pm—
- 8pm–5am—
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
The 8am–11am window is the strongest at 87.2% on time. The full set of windows spans 2 points.
Across the year
Southwest on SLC to BNA through the year
- Jul–Sep 202530 flights86.7%
- Oct–Dec 202592 flights87.0%
- Jan–Mar 202650 flights97.9%
- Apr–Jun 202638 flights86.8%
- Jul–Sep 202662 flights71.0%
Scale runs 65% to 100%.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 85.2% on time across 272 flights.
Southwest on SLC to BNA did not run the same all year. Its best quarter was Jan–Mar 2026 at 97.9% on time and its weakest Jul–Sep 2026 at 71.0%, a swing of 27 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, Saturday is the strongest day at 93.2% on time and Sunday the weakest at 70.7%, a spread of 23 points.
Arrival by arrival
How late Southwest on SLC to BNA runs when it is late
Most of the lateness is short. 24 of the 40 late arrivals were under half an hour behind, and 5 reached an hour or more.
- 15+ min early52 flights19.3%
- Within 15 min178 flights65.9%
- 15–29 min late24 flights8.9%
- 30–59 min late11 flights4.1%
- 1–2 hours late2 flights0.7%
- 2+ hours late3 flights1.1%
Scale runs 0% to 100%.
Share of 270 completed flights by arrival against schedule.
A late pushback is often recovered here: of 51 departures that left 15 minutes late or more, 22 still arrived on time. 11 flights left on time and still arrived late.
The worst days
Worst days for Southwest on SLC to BNA
The latest arrival of the period was on 22 November 2025, 4 hours 42 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across November, June, July and October, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 22 November 2025 | 4 hours 42 minutes | Carrier |
| 27 June 2026 | 2 hours 19 minutes | Extreme weather |
| 9 November 2025 | 2 hours | National Airspace System |
| 12 July 2026 | 1 hour 52 minutes | Late-arriving aircraft |
| 10 October 2025 | 1 hour 41 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
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 1,654 reported delay minutes.
- 38%Carrier
- 33%Late-arriving aircraft
- 22%National Airspace System
- 8%Extreme weather
The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 621 of the 1,654 delay minutes reported here. The split is drawn from 1,654 reported delay minutes.
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 87.2% on time here.
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
Badly late arrivals are rare here: only 1.9% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 71.1% on time across 272 flights, 14 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 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 SLC to BNA
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 85.2% 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
- SLC to BNA, every carrier
- Southwest on BNA to SLC, the return leg
- Delta Air Lines on SLC to BNA85.0%
- Southwest Airlines network-wide record
- Salt Lake City International (SLC) delay statistics
- Nashville International (BNA) delay statistics
- Why the first flight of the morning is statistically safest
- How to read this site: grades, sample sizes, and honest caveats
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.