Route reliability record
DAL→SAT
Dallas to San Antonio
- Flights
- 2,728
- Period
- July 2025 to June 2026
- Distance
- 247 mi
- Carriers
- 1
This route lands a B, level with the national rate of 77.6%. Roughly 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 2,728 flights, with a median arrival 7 minutes early.
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
77.8%
Arrivals under 15 minutes late, of 2,694 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.14%
National rate is 1.81%
Best carrier
Southwest
77.8% on time across 2,728 flights
These figures cover 2,728 flights between July 2025 and June 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 DAL to SAT
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 2,728 | 77.8% | 58 min | 1.14% | B |
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 39 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–8am379 flights95.7%
- 8am–11am456 flights94.8%
- 11am–2pm602 flights82.5%
- 2pm–5pm441 flights73.7%
- 5pm–8pm457 flights62.3%
- 8pm–5am393 flights56.3%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 56.3% on time, against 95.7% 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 11am–2pm window is the busiest, with 602 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 29 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 57.5% on time, 29 points below October, the best at 86.6%. 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. October was the busiest month here, with 254 flights.
Across the week, Tuesday is the strongest day at 85.0% on time and Sunday the weakest at 71.0%. 14 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 61% of the 34,000 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.
- 61%Late-arriving aircraft
- 29%Carrier
- 8%National Airspace System
- 2%Extreme weather
- 0%Security
61% 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 34,000 reported delay minutes here, that single category outweighs weather by 30 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 33,889 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 95.7% on time here.
Cancellations sit at 1.14% against a national 1.81%, which is ordinary. Diversions add another 0.11%.
Connections and stage length
What a delay here actually costs
6.9% 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.
At 247 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 83.2% on time across 2,728 flights, 5 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 5 points of difference.
The sample behind these figures is 2,728 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. October runs 86.6% on time and June 57.5%, a swing of 29 points. If the dates move at all, move them out of June before you think about anything else. 2,694 completed flights over 12 months sit behind that.
Common questions
DAL to SAT questions
How often is DAL to SAT delayed?
Roughly 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 22.2% of the 2,728 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is DAL to SAT compared with the rest of the country?
77.8% of flights arrive on time here against a national 77.6%, a difference of half a point in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on DAL to SAT?
The 5am–8am departure window is the strongest at 95.7% on time. The 8pm–5am window is the weakest at 56.3%, 39 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 DAL to SAT?
June is the weakest month at 57.5% on time, compared with 86.6% in October. Across the year that is 29 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
- SAT to DAL — the return legseparate record
- Dallas Love Field (DAL) delay statistics
- San Antonio International (SAT) delay statistics
- Southwest Airlines on-time record77.8%
- 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. DAL to SAT and SAT to DAL 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.