Route reliability record
AUS→ATL
Austin to Atlanta
- Flights
- 4,565
- Period
- June 2025 to May 2026
- Distance
- 813 mi
- Carriers
- 4
This route lands a B, 4 points 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 4,565 flights, of which Delta Air Lines flew 3,263 at 84.5% 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
81.1%
Arrivals under 15 minutes late, of 4,485 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.56%
National rate is 1.80%
Best carrier
Delta
84.5% on time across 3,263 flights
These figures cover 4,565 flights between June 2025 and May 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
Which airline is most reliable on AUS to ATL
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 84.5% of the time; Southwest Airlines manages 78.0%. Sample sizes sit next to every figure, because a two-point gap across 1,036 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines | 3,263 | 84.5% | 68 min | 1.62% | B |
| Southwest Airlines | 1,036 | 78.0% | 57 min | 0.68% | B+ |
| Frontier Airlinesthin sample | 265 | 50.0% | 76 min | 4.15% | F− |
Delta leads Southwest by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 28 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am764 flights94.7%
- 8am–11am957 flights90.7%
- 11am–2pm967 flights84.2%
- 2pm–5pm809 flights71.3%
- 5pm–8pm1,047 flights66.9%
- 8pm–5am21 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 94.7% of the time, against 66.9% for the evening window. That is 28 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 23 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 67.5% on time, 23 points below September, the best at 90.6%. 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.
Across the week, Tuesday is the strongest day at 86.7% on time and Sunday the weakest at 73.5%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 56,000 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.
- 48%Late-arriving aircraft
- 27%Carrier
- 21%National Airspace System
- 4%Extreme weather
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 56,000 reported delay minutes here, that single category outweighs weather by 14 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 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 94.7% on time here.
Cancellations sit at 1.56% against a national 1.80%, which is ordinary. Diversions add another 0.20%.
Connections and stage length
What a delay here actually costs
6.2% 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 78.4% on time across 4,566 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 4,565 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. September runs 90.6% on time and June 67.5%, a swing of 23 points. If the dates move at all, move them out of June before you think about anything else.
Common questions
AUS to ATL questions
How often is AUS to ATL 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 18.9% of the 4,565 flights in this analysis, against 22.6% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on AUS to ATL?
Delta Air Lines leads at 84.5% on time across 3,263 flights. Southwest Airlines is at the other end on 78.0%, a gap of 7 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 AUS to ATL?
The 5am–8am departure window is the strongest at 94.7% on time. The 5pm–8pm window is the weakest at 66.9%, 28 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 AUS to ATL?
June is the weakest month at 67.5% on time, compared with 90.6% in September. Across the year that is 23 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
- ATL to AUS — the return legseparate record
- Austin-Bergstrom International (AUS) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- American Airlines on-time record100.0%
- Delta Air Lines on-time record84.5%
- Southwest Airlines on-time record78.0%
- 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. AUS to ATL and ATL to AUS 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.