Route reliability record
SAT→ATL
San Antonio to Atlanta
- Flights
- 3,026
- Period
- July 2025 to June 2026
- Distance
- 874 mi
- Carriers
- 4
This route earns a A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 3,026 flights, with a median arrival 9 minutes early.
Set against the rest of the country, this route's record is 9 points better than the US average of 77.6%. That gap is worth roughly 85 fewer late arrivals for every thousand flights.
Key figures
On time
86.1%
Arrivals under 15 minutes late, of 2,964 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
1.55%
National rate is 1.81%
Best carrier
Delta
87.8% on time across 2,609 flights
These figures cover 3,026 flights between July 2025 and June 2026. The median arrival is 9 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 SAT to ATL
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 2,609 | 87.8% | 75 min | 1.76% | A |
| Southwest Airlinesthin sample | 318 | 79.9% | 46 min | 0.31% | B+ |
| Spirit Airlinesthin sample | 8 | 75.0% | 31 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 91 | 62.2% | 99 min | 0.00% | D+ |
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 18 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–8am752 flights93.5%
- 8am–11am528 flights91.9%
- 11am–2pm720 flights85.6%
- 2pm–5pm555 flights75.6%
- 5pm–8pm471 flights81.0%
- 8pm–5am—
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.5% of the time, against 75.6% for the afternoon window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 752 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 18 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.
July is the worst month at 76.7% on time, 18 points below September, the best at 94.6%. 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. July was the busiest month here, with 277 flights.
Across the week, Wednesday is the strongest day at 92.0% on time and Sunday the weakest at 82.0%. 10 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 30,000 reported delay minutes.
- 41%Late-arriving aircraft
- 39%Carrier
- 17%National Airspace System
- 3%Extreme weather
41% 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 30,000 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 split is drawn from 29,715 reported delay minutes.
The largest share of delay minutes, 39%, 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 11,000 of the 30,000 delay minutes reported here.
Cancellations sit at 1.55% against a national 1.81%, which is ordinary. Diversions add another 0.50%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.8% 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 874 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 81.2% on time across 3,027 flights, 5 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 5 points of difference.
The sample behind these figures is 3,026 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 94.6% on time and July 76.7%, a swing of 18 points. If the dates move at all, move them out of July before you think about anything else. 2,964 completed flights over 12 months sit behind that.
Common questions
SAT to ATL questions
How often is SAT to ATL delayed?
About one flight in seven arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 13.9% of the 3,026 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is SAT to ATL compared with the rest of the country?
86.1% of flights arrive on time here against a national 77.6%, a difference of 9 points in its favour. That is worth a A on this site's grading scale.
What time of day has the fewest delays on SAT to ATL?
The 5am–8am departure window is the strongest at 93.5% on time. The 2pm–5pm window is the weakest at 75.6%, 18 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 July delays on SAT to ATL?
July is the weakest month at 76.7% on time, compared with 94.6% in September. Across the year that is 18 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 SAT — the return legseparate record
- San Antonio International (SAT) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record87.8%
- Southwest Airlines on-time record79.9%
- Spirit Airlines on-time record75.0%
- 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. SAT to ATL and ATL to SAT 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.