Route reliability record
SLC→AUS
Salt Lake City to Austin
- Flights
- 1,783
- Period
- July 2025 to June 2026
- Distance
- 1,086 mi
- Carriers
- 3
This route lands a B+, 5 points better than the national rate of 77.6%. About one flight in six 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 1,783 SLC to AUS flights, of which Delta Air Lines flew 1,081 at 82.6% on time.
Best time to fly SLC to AUS: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 92.9% of the time and Wednesday flights 87.0%, against 82.1% for the route overall.
Set against the rest of the country, this route's record is 5 points better than the US average of 77.6%. That gap is worth roughly 45 fewer late arrivals for every thousand flights.
Key figures
On time
82.1%
Arrivals under 15 minutes late, of 1,767 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.81%
Best carrier
Delta
82.6% on time across 1,081 flights
These figures cover 1,783 flights between July 2025 and June 2026. The median arrival is 7 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
Which airline is most reliable on SLC to AUS
The two carriers here are closely matched: 4 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 232 | 87.8% | 53 min | 0.86% | A+ |
| Delta Air Lines | 1,081 | 82.6% | 66 min | 0.56% | B+ |
| Southwest Airlines | 470 | 78.2% | 50 min | 0.64% | B+ |
No carrier stands out. Delta tops the table at 82.6%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on SLC to AUS
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Salt Lake City to Austin
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SLC → AUSSalt Lake City to Austin | Delta Air Lines | 82.1% | 82.6% | 0.56% | 11am–2pm, Wed | DL 2728 17:15 |
| 2. SLC → AUSSalt Lake City to Austin | Southwest Airlines | 77.7% | 78.2% | 0.64% | 5am–8am, Mon | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am99 flights92.9%
- 8am–11am492 flights86.1%
- 11am–2pm267 flights81.3%
- 2pm–5pm341 flights77.8%
- 5pm–8pm407 flights77.8%
- 8pm–5am177 flights84.4%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.9% of the time, against 77.8% for the evening window. That is 15 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 492 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 64.7% on time, 23 points below September, the best at 88.0%. 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. March was the busiest month here, with 170 flights.
Across the week, Wednesday is the strongest day at 87.0% on time and Sunday the weakest at 78.4%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 51% of the 19,000 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%Carrier
- 27%Late-arriving aircraft
- 19%National Airspace System
- 3%Extreme weather
- 0%Security
The largest share of delay minutes, 51%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 9,506 of the 19,000 delay minutes reported here. The split is drawn from 18,717 reported delay minutes.
Cancellations are rare at 0.62%, below the national 1.81% 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 actually costs
Badly late arrivals are rare here: only 4.9% land an hour or more behind schedule, against 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 82.4% on time across 1,784 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,783 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in AUS after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 88.0% on time and July 64.7%, a swing of 23 points. If the dates move at all, move them out of July before you think about anything else. 1,767 completed flights over 12 months sit behind that.
Common questions
SLC to AUS questions
How often is SLC to AUS delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.9% of the 1,783 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on SLC to AUS?
Delta Air Lines leads at 82.6% on time across 1,081 flights. Southwest Airlines is at the other end on 78.2%, a gap of 4 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on SLC to AUS?
The 5am–8am departure window is the strongest at 92.9% on time. The 5pm–8pm window is the weakest at 77.8%, 15 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on SLC to AUS?
July is the weakest month at 64.7% on time, compared with 88.0% in September. Across the year that is 23 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- AUS to SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- SkyWest Airlines on SLC to AUS87.8%
- Delta Air Lines on SLC to AUS82.6%
- Southwest Airlines on SLC to AUS78.2%
- SLC to DEN, a related route77.8%
- DEN to AUS, a related route76.1%
- SLC to PHX, a related route83.9%
- SkyWest Airlines on-time record87.8%
- Delta Air Lines on-time record82.6%
- Southwest Airlines on-time record78.2%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SLC to AUS and AUS to SLC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.