Route reliability record
ATL→AUS
Atlanta to Austin
- Flights
- 4,566
- Period
- June 2025 to May 2026
- Distance
- 813 mi
- Carriers
- 4
This route lands a B, about a point better than the national rate of 77.4%. About one flight in five arrive 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 4,566 flights, of which Southwest Airlines flew 1,036 at 80.6% on time.
The US average over the same twelve months is 77.4%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.4%
Arrivals under 15 minutes late, of 4,491 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.51%
National rate is 1.80%
Best carrier
Southwest
80.6% on time across 1,036 flights
These figures cover 4,566 flights between June 2025 and May 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 ATL to AUS
The two carriers here are closely matched: 2 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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,036 | 80.6% | 51 min | 0.58% | B+ |
| Delta Air Lines | 3,264 | 78.7% | 57 min | 1.62% | B |
| Frontier Airlinesthin sample | 265 | 65.1% | 77 min | 3.77% | C− |
| American Airlinesthin sample | 1 | 0.0% | 35 min | 0.00% | F+ |
No carrier stands out. Southwest tops the table at 80.6%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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 26 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am88 flights95.3%
- 8am–11am939 flights89.1%
- 11am–2pm941 flights86.4%
- 2pm–5pm1,137 flights72.6%
- 5pm–8pm798 flights69.9%
- 8pm–5am663 flights69.6%
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 95.3% of the time, against 69.6% for the overnight 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.
Across the year
When delays peak on this route
This route's year swings by 34 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.
June is the worst month at 59.0% on time, 34 points below February, the best at 92.7%. 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.
Across the week, Wednesday is the strongest day at 85.6% on time and Sunday the weakest at 70.0%. 16 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 56,000 reported delay minutes.
- 40%Carrier
- 33%Late-arriving aircraft
- 23%National Airspace System
- 4%Extreme weather
- 0%Security
The largest share of delay minutes, 40%, 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 22,000 of the 56,000 delay minutes reported here.
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 95.3% on time here.
Cancellations sit at 1.51% against a national 1.80%, which is ordinary. Diversions add another 0.13%.
Connections and stage length
What a delay here actually costs
6.6% of arrivals land an hour or more late, close to the national 8.2%. 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 are the about an hour kind, 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 runs 81.1% on time across 4,565 flights, within 3 points 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 4,566 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.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 92.7% on time and June 59.0%, a swing of 34 points. If the dates move at all, move them out of June before you think about anything else.
Common questions
ATL to AUS questions
How often is ATL to AUS delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.6% of the 4,566 flights in this analysis, against 22.6% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on ATL to AUS?
Southwest Airlines leads at 80.6% on time across 1,036 flights. Delta Air Lines is at the other end on 78.7%, a gap of 2 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 ATL to AUS?
The 5am–8am departure window is the strongest at 95.3% on time. The 8pm–5am window is the weakest at 69.6%, 26 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 June delays on ATL to AUS?
June is the weakest month at 59.0% on time, compared with 92.7% in February. Across the year that is 34 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 ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- Southwest Airlines on-time record80.6%
- Delta Air Lines on-time record78.7%
- Frontier Airlines on-time record65.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. ATL to AUS and AUS to ATL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.