Carrier route record

DLAUS→MIA

Delta Air Lines · Austin to Miami

Flights: 221
Period: July 2025 to June 2026
Share of route: 10%
Carriers: 6

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

Delta on AUS to MIA earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 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 221 flights, with a median arrival 13 minutes early.

Set against the rest of the country, Delta's AUS to MIA record is 12 points better than the US average of 77.6%. That gap is worth roughly 118 fewer late arrivals for every thousand flights.

On time

89.4%

Arrivals under 15 minutes late, of 218 completed flights

Avg delay

84 min

Across delayed arrivals only, not all flights

Cancelled

1.36%

National rate is 1.81%

Whole route

78.5%

Every carrier on AUS to MIA, 2,161 flights

These figures cover 221 flights between July 2025 and June 2026. The median arrival is 13 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 MIA

Delta flew 221 of the 2,161 flights on AUS to MIA, about 10% of it. Its 89.4% on time is 11 points better than the route as a whole, which runs 78.5%. Ranked by on-time rate it is number two of six carriers on the route, where the range runs from Spirit at 100.0% to Southwest at 67.3%. Four 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 MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	1	100.0%	—	0.00%	A+
Delta Air Lines (this page)thin sample	221	89.4%	84 min	1.36%	A
American Airlines	1,522	79.8%	82 min	1.38%	B
Envoy Airthin sample	22	72.7%	61 min	0.00%	C+
Frontier Airlinesthin sample	46	71.7%	82 min	0.00%	C+
Southwest Airlinesthin sample	349	67.3%	47 min	0.86%	C+

Departure window

When Delta 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 221 flights.

There are not enough flights in each departure window to split Delta's AUS to MIA record by time of day without the percentages moving on noise. The headline rate of 89.4% is the reliable figure here.

Across the year

Delta on AUS to MIA through the year

Oct–Dec 202540 flights87.5%
Jan–Mar 202690 flights87.6%
Apr–Jun 202691 flights92.1%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 89.4% on time across 221 flights.

Quarter by quarter Delta on AUS to MIA held fairly steady: 87.5% in Oct–Dec 2025, 87.6% in Jan–Mar 2026 and 92.1% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Tuesday is the strongest day at 93.8% on time and Saturday the weakest at 81.2%. 13 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 73% of the 1,929 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
73%
National Airspace System
16%
Late-arriving aircraft
6%
Extreme weather
5%

The largest share of delay minutes, 73%, 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 1,406 of the 1,929 delay minutes reported here. The split is drawn from 1,929 reported delay minutes.

Cancellations sit at 1.36% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.1% 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 1,103 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 69.1% on time across 222 flights, 20 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 20 points of difference.

One caution: this is a thin sample. 221 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 MIA

Put together: treat all of this as provisional. 221 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 89.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 218 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