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DelayAtlas

Carrier route record

WNAUSATL

Southwest Airlines · Austin to Atlanta

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

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

Southwest on AUS to ATL lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 1,036 flights, with a median arrival 6 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on AUS to ATL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

78.8%

Arrivals under 15 minutes late, of 1,026 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.68%

National rate is 1.81%

Whole route

82.0%

Every carrier on AUS to ATL, 4,544 flights

These figures cover 1,036 flights between July 2025 and June 2026. The median arrival is 6 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 AUS to ATL

Southwest flew 1,036 of the 4,544 flights on AUS to ATL, about 23% of it. Its 78.8% on time is 3 points worse than the route as a whole, which runs 82.0%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from American at 100.0% to Frontier at 52.1%. 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 AUS to ATL
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlinesthin sample1100.0%0.00%A+
Delta Air Lines3,23285.6%73 min1.49%A
Southwest Airlines (this page)1,03678.8%53 min0.68%B+
Frontier Airlinesthin sample27552.1%74 min3.64%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 44 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–8am56 flights96.4%
  • 8am–11am303 flights94.7%
  • 11am–2pm222 flights84.5%
  • 2pm–5pm314 flights68.2%
  • 5pm–8pm118 flights52.5%
  • 8pm–5am23 flights

Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 52.5% on time, against 96.4% 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 2pm–5pm window is the busiest, with 314 flights scheduled in it.

Across the year

Southwest on AUS to ATL through the year

On-time rate by calendar month93J81F72M77A59M73J67J83A95S81O82N82D
Darker means more delays. Figures are on-time percentages.September best, May worst

September is the best month on the calendar at 95.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 91 flights.

Across the week, Wednesday is the strongest day at 86.6% on time and Sunday the weakest at 72.5%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week73.7Mon84.2Tue86.6Wed76.6Thu75.7Fri83.3Sat72.5Sun
Monday: 73.7 percent on time. Tuesday: 84.2 percent on time. Wednesday: 86.6 percent on time. Thursday: 76.6 percent on time. Friday: 75.7 percent on time. Saturday: 83.3 percent on time. Sunday: 72.5 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 49% of the 12,000 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.

  • Late-arriving aircraft
    49%
  • Carrier
    30%
  • National Airspace System
    19%
  • Extreme weather
    2%

49% 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 12,000 reported delay minutes here, that single category outweighs weather by 25 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 11,598 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 96.4% on time here.

Cancellations are rare at 0.68%, 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

6.1% 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 roughly 55 minutes, which a normal layover absorbs.

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 81.9% on time across 1,036 flights, 3 points above 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 AUS to ATL

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 78.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,026 completed flights over 12 months sit behind that.

Related

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.