Route reliability record
AUS→SAN
Austin to San Diego
- Flights
- 2,545
- Period
- July 2025 to June 2026
- Distance
- 1,164 mi
- Carriers
- 3
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,545 flights, of which SkyWest Airlines flew 1,000 at 81.9% on time.
The US average over the same twelve months is 77.6%, 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
75.0%
Arrivals under 15 minutes late, of 2,507 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
1.06%
National rate is 1.81%
Best carrier
SkyWest
81.9% on time across 1,000 flights
These figures cover 2,545 flights between July 2025 and June 2026. The median arrival is 3 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 SAN
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 81.9% of the time; Southwest Airlines manages 70.4%. Sample sizes sit next to every figure, because a two-point gap across 1,422 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 1,000 | 81.9% | 63 min | 1.50% | B |
| Frontier Airlinesthin sample | 123 | 73.3% | 94 min | 2.44% | C |
| Southwest Airlines | 1,422 | 70.4% | 54 min | 0.63% | C+ |
SkyWest leads Southwest by 12 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 38 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am665 flights91.3%
- 8am–11am113 flights85.6%
- 11am–2pm367 flights80.2%
- 2pm–5pm610 flights73.5%
- 5pm–8pm266 flights53.8%
- 8pm–5am524 flights60.9%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 53.8% on time, against 91.3% 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 5am–8am window is the busiest, with 665 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 21 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 63.0% on time, 21 points below January, the best at 84.0%. 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. March was the busiest month here, with 254 flights.
Across the week, Saturday is the strongest day at 83.9% on time and Sunday the weakest at 67.6%. 16 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 58% of the 37,000 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.
- 58%Late-arriving aircraft
- 26%Carrier
- 13%National Airspace System
- 3%Extreme weather
- 0%Security
58% 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 37,000 reported delay minutes here, that single category outweighs weather by 19 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 36,805 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 91.3% on time here.
Cancellations sit at 1.06% against a national 1.81%, which is ordinary. Diversions add another 0.43%.
Connections and stage length
What a delay here actually costs
7.7% 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 are the about an hour kind, which a normal layover absorbs.
The 1,164 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 73.0% on time across 2,552 flights, within 2 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 2,545 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. January runs 84.0% on time and June 63.0%, a swing of 21 points. If the dates move at all, move them out of June before you think about anything else. 2,507 completed flights over 12 months sit behind that.
Common questions
AUS to SAN questions
How often is AUS to SAN delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.0% of the 2,545 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on AUS to SAN?
SkyWest Airlines leads at 81.9% on time across 1,000 flights. Southwest Airlines is at the other end on 70.4%, a gap of 12 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 SAN?
The 5am–8am departure window is the strongest at 91.3% on time. The 5pm–8pm window is the weakest at 53.8%, 38 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 SAN?
June is the weakest month at 63.0% on time, compared with 84.0% in January. Across the year that is 21 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
- SAN to AUS — the return legseparate record
- Austin-Bergstrom International (AUS) delay statistics
- San Diego International (SAN) delay statistics
- SkyWest Airlines on-time record81.9%
- Frontier Airlines on-time record73.3%
- Southwest Airlines on-time record70.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. AUS to SAN and SAN 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, July 2025 to June 2026. Updated monthly. How this data is collected.