Carrier route record
WNSLC→AUS
Southwest Airlines · Salt Lake City to Austin
- Flights
- 482
- Period
- September 2025 to August 2026
- Share of route
- 27%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SLC to AUS lands a B+, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That rests on 482 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on SLC to AUS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.2%
Arrivals under 15 minutes late, of 479 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.89%
Whole route
81.5%
Every carrier on SLC to AUS, 1,796 flights
These figures cover 482 flights between September 2025 and August 2026. The median arrival is 2 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 AUS
Southwest flew 482 of the 1,796 flights on SLC to AUS, about 27% of it. Its 76.2% on time is 5 points worse than the route as a whole, which runs 81.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 84.5% to Southwest at 76.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 242 | 84.5% | 50 min | 0.83% | B+ |
| Delta Air Lines | 1,072 | 83.2% | 62 min | 0.65% | B+ |
| Southwest Airlines (this page) | 482 | 76.2% | 50 min | 0.62% | B+ |
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 matters more here than the choice of carrier. The gap between the best and worst window is 67 points, against half a point between the best and worst carrier.
- 5am–8am88 flights96.6%
- 8am–11am50 flights80.0%
- 11am–2pm173 flights79.2%
- 2pm–5pm101 flights75.0%
- 5pm–8pm47 flights29.8%
- 8pm–5am23 flights—
Scale runs 20% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 29.8% on time, against 96.6% for the 5am–8am 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. The 11am–2pm window is the busiest, with 173 flights scheduled in it.
Across the year
Southwest on SLC to AUS through the year
June is the worst month at 57.1% on time, 40 points below September, the best at 96.7%. 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. July was the busiest month here, with 54 flights.
Across the week, Wednesday is the strongest day at 80.0% on time and Saturday the weakest at 68.2%, a spread of 12 points.
Arrival by arrival
How late Southwest on SLC to AUS runs when it is late
The 114 late arrivals split 46 under half an hour, 46 between 30 and 60 minutes, and 22 an hour or more.
- 15+ min early81 flights16.9%
- Within 15 min284 flights59.3%
- 15–29 min late46 flights9.6%
- 30–59 min late46 flights9.6%
- 1–2 hours late13 flights2.7%
- 2+ hours late9 flights1.9%
Scale runs 0% to 100%.
Share of 479 completed flights by arrival against schedule.
25 of 122 late departures made up the time and arrived on time, 20% of them. 17 flights left on time and still arrived late.
The worst days
Worst days for Southwest on SLC to AUS
The latest arrival of the period was on 7 August 2026, 5 hours 3 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 |
|---|---|---|
| 7 August 2026 | 5 hours 3 minutes | Late-arriving aircraft |
| 18 February 2026 | 4 hours 7 minutes | Late-arriving aircraft |
| 17 December 2025 | 3 hours 48 minutes | Late-arriving aircraft |
| 23 January 2026 | 3 hours 32 minutes | Carrier |
| 2 July 2026 | 2 hours 44 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 65% of the 5,674 delay minutes carriers reported here, and the remaining four split what is left.
- 65%Late-arriving aircraft
- 18%Carrier
- 16%National Airspace System
- 1%Extreme weather
- 0%Security
65% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,674 reported delay minutes here, that single category outweighs weather by 65 to one. The split is drawn from 5,674 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 96.6% on time here.
Cancellations are rare at 0.62%, 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 4.6% 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 1,086 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 68.0% on time across 482 flights, 8 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 8 points of difference.
One caution: this is a thin sample. 482 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 AUS
Put together: treat all of this as provisional. 482 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 76.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 479 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to AUS, every carrier
- Southwest on AUS to SLC, the return leg
- SkyWest Airlines on SLC to AUS84.5%
- Delta Air Lines on SLC to AUS83.2%
- Southwest Airlines network-wide record
- Salt Lake City International (SLC) delay statistics
- Austin-Bergstrom International (AUS) 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.