Carrier route record

DLAUS→SLC

Delta Air Lines · Austin to Salt Lake City

Flights: 1,081
Period: July 2025 to June 2026
Share of route: 61%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on AUS to SLC 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 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 1,081 flights, with a median arrival 10 minutes early.

Set against the rest of the country, Delta's AUS to SLC record is 9 points better than the US average of 77.6%. That gap is worth roughly 89 fewer late arrivals for every thousand flights.

On time

86.5%

Arrivals under 15 minutes late, of 1,073 completed flights

Avg delay

93 min

Across delayed arrivals only, not all flights

Cancelled

0.74%

National rate is 1.81%

Whole route

82.4%

Every carrier on AUS to SLC, 1,784 flights

These figures cover 1,081 flights between July 2025 and June 2026. The median arrival is 10 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

Delta against every carrier on AUS to SLC

Delta flew 1,081 of the 1,784 flights on AUS to SLC, most of the route. Its 86.5% on time is 4 points better than the route as a whole, which runs 82.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 87.8% to Southwest at 70.6%. 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.

On-time performance by carrier on AUS to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	233	87.8%	72 min	1.29%	A
Delta Air Lines (this page)	1,081	86.5%	93 min	0.74%	A+
Southwest Airlines	470	70.6%	58 min	0.21%	C+

Flight by flight

Delta flight numbers on AUS to SLC

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am48 flights89.4%
8am–11am317 flights94.9%
11am–2pm359 flights82.6%
2pm–5pm—
5pm–8pm356 flights82.7%
8pm–5am1 flights—

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 82.6% on time against 94.9% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 359 flights scheduled in it.

Across the year

Delta on AUS to SLC through the year

Darker means more delays. Figures are on-time percentages.September best, July worst

July is the worst month at 75.0% on time, 21 points below September, the best at 95.6%. 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. January was the busiest month here, with 93 flights.

Across the week, Tuesday is the strongest day at 90.5% on time and Thursday the weakest at 83.6%. 7 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 53% of the 14,000 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.

Carrier
53%
Late-arriving aircraft
38%
National Airspace System
6%
Extreme weather
3%
Security
0%

38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 14,000 reported delay minutes here, that single category outweighs weather by 13 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 13,510 reported delay minutes.

The largest share of delay minutes, 53%, 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 7,158 of the 14,000 delay minutes reported here.

Cancellations are rare at 0.74%, 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 costs

5.4% 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 an hour and a half, which a normal layover absorbs.

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 is a different operation and performs like one: it runs 82.6% on time across 1,081 flights, 4 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 4 points of difference.

One caution: this is a thin sample. 1,081 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 Delta on AUS to SLC

Put together: treat all of this as provisional. 1,081 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 86.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,073 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures