Carrier route record

WNATL→AUS

Southwest Airlines · Atlanta to Austin

Flights: 1,036
Period: July 2025 to June 2026
Share of route: 23%
Carriers: 4

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

Southwest on ATL to AUS lands a B+, 4 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 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,036 flights, with a median arrival 8 minutes early.

Set against the rest of the country, Southwest's ATL to AUS record is 4 points better than the US average of 77.6%. That gap is worth roughly 43 fewer late arrivals for every thousand flights.

On time

81.9%

Arrivals under 15 minutes late, of 1,029 completed flights

Avg delay

49 min

Across delayed arrivals only, not all flights

Cancelled

0.58%

National rate is 1.81%

Whole route

79.8%

Every carrier on ATL to AUS, 4,545 flights

These figures cover 1,036 flights between July 2025 and June 2026. The median arrival is 8 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

Southwest against every carrier on ATL to AUS

Southwest flew 1,036 of the 4,545 flights on ATL to AUS, about 23% of it. Its 81.9% on time is 2 points better than the route as a whole, which runs 79.8%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from Southwest at 81.9% to American at 0.0%. Two 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 ATL to AUS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines (this page)	1,036	81.9%	49 min	0.58%	B+
Delta Air Lines	3,233	80.2%	57 min	1.48%	B
Frontier Airlinesthin sample	275	66.5%	78 min	3.27%	C−
American Airlinesthin sample	1	0.0%	35 min	0.00%	F+

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 26 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–8am110 flights96.3%
8am–11am159 flights89.7%
11am–2pm237 flights90.2%
2pm–5pm206 flights79.6%
5pm–8pm306 flights69.9%
8pm–5am18 flights—

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 96.3% of the time, against 69.9% for the evening window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 306 flights scheduled in it.

Across the year

Southwest on ATL to AUS through the year

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

July is the worst month at 65.2% on time, 29 points below September, the best at 94.2%. 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. December was the busiest month here, with 91 flights.

Across the week, Wednesday is the strongest day at 91.0% on time and Monday the weakest at 72.9%. 18 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 9,156 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.

Late-arriving aircraft
48%
Carrier
25%
National Airspace System
23%
Extreme weather
4%

48% 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 9,156 reported delay minutes here, that single category outweighs weather by 11 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 9,156 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 96.3% on time here.

Cancellations are rare at 0.58%, 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

Badly late arrivals are rare here: only 4.7% 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 813 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 78.8% on time across 1,036 flights, 3 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 3 points of difference.

One caution: this is a thin sample. 1,036 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 ATL to AUS

Put together: treat all of this as provisional. 1,036 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 81.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,029 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