Route reliability record
SAT→HOU
San Antonio to Houston
- Flights
- 1,378
- Period
- July 2025 to June 2026
- Distance
- 192 mi
- Carriers
- 1
This route sits in the middle of the pack with a C+. 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 50 minutes behind schedule. That rests on 1,378 SAT to HOU flights, with a median arrival 4 minutes early.
Best time to fly SAT to HOU: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 94.0% of the time and Tuesday flights 79.6%, against 74.5% for the route overall.
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
74.5%
Arrivals under 15 minutes late, of 1,373 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.29%
National rate is 1.81%
Best carrier
Southwest
74.5% on time across 1,378 flights
These figures cover 1,378 flights between July 2025 and June 2026. The median arrival is 4 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 HOU
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 | 1,378 | 74.5% | 50 min | 0.29% | C+ |
Best ways to make this trip
The most reliable ways to fly San Antonio to Houston
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SAT → IAHSan Antonio to Houston | United Airlines | 80.9% | 81.5% | 0.69% | 11am–2pm, Tue (route) | — |
| 2. SAT → HOUSan Antonio to Houston | Southwest Airlines | 74.3% | 74.5% | 0.29% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 42 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–8am364 flights94.0%
- 8am–11am183 flights89.0%
- 11am–2pm260 flights72.1%
- 2pm–5pm109 flights75.2%
- 5pm–8pm359 flights52.1%
- 8pm–5am103 flights63.1%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 52.1% on time, against 94.0% 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 364 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 32 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.
Delays peak in May, when the on-time rate falls to 55.3%. December is the strongest month at 87.7%. Moving a flexible trip across that boundary buys 32 points. August was the busiest month here, with 144 flights.
Across the week, Tuesday is the strongest day at 79.6% on time and Thursday the weakest at 68.7%. 11 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 45% of the 18,000 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.
- 45%Late-arriving aircraft
- 34%National Airspace System
- 19%Carrier
- 1%Extreme weather
- 0%Security
45% 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 18,000 reported delay minutes here, that single category outweighs weather by 42 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 17,569 reported delay minutes.
34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 6,012 minutes out of 18,000, against a national NAS share of 21%.
Cancellations are rare at 0.29%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
6.3% 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 last about 50 minutes, which a normal layover absorbs.
At 192 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 78.3% on time across 1,370 flights, 4 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 4 points of difference.
The sample behind these figures is 1,378 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.
Work out the risk of missing a connection in HOU after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. December runs 87.7% on time and May 55.3%, a swing of 32 points. If the dates move at all, move them out of May before you think about anything else. 1,373 completed flights over 12 months sit behind that.
Common questions
SAT to HOU questions
How often is SAT to HOU delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.5% of the 1,378 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 50 minutes on average.
How reliable is SAT to HOU compared with the rest of the country?
74.5% of flights arrive on time here against a national 77.6%, a difference of 3 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on SAT to HOU?
The 5am–8am departure window is the strongest at 94.0% on time. The 5pm–8pm window is the weakest at 52.1%, 42 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 May delays on SAT to HOU?
May is the weakest month at 55.3% on time, compared with 87.7% in December. Across the year that is 32 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
- HOU to SAT — the return legseparate record
- San Antonio International (SAT) delay statistics
- William P. Hobby (HOU) delay statistics
- SAT to DFW, a related route77.1%
- DAL to HOU, a related route74.1%
- SAT to DEN, a related route81.0%
- Southwest Airlines on-time record74.5%
- 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 HOU and HOU to SAT are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.