Carrier route record
UASAT→IAH
United Airlines · San Antonio to Houston
- Flights
- 2,245
- Period
- September 2025 to August 2026
- Share of route
- 95%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on SAT to IAH lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 2,245 flights, with a median arrival 7 minutes early.
Set against the rest of the country, United's SAT to IAH record is 6 points better than the US average of 77.3%. That gap is worth roughly 55 fewer late arrivals for every thousand flights.
Key figures
On time
82.8%
Arrivals under 15 minutes late, of 2,233 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.45%
National rate is 1.89%
Whole route
83.0%
Every carrier on SAT to IAH, 2,372 flights
These figures cover 2,245 flights between September 2025 and August 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.
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Carrier by carrier
United against every carrier on SAT to IAH
United flew 2,245 of the 2,372 flights on SAT to IAH, most of the route. Its 82.8% on time is about level with the route as a whole at 83.0%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 87.3% to United at 82.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 127 | 87.3% | 69 min | 0.79% | A+ |
| United Airlines (this page) | 2,245 | 82.8% | 59 min | 0.45% | B+ |
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Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 11 points, against half a point between the best and worst carrier.
- 5am–8am602 flights85.7%
- 8am–11am347 flights83.7%
- 11am–2pm243 flights89.3%
- 2pm–5pm624 flights78.8%
- 5pm–8pm429 flights80.1%
- 8pm–5am—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 89.3% on time, ahead of 2pm–5pm at 78.8%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 2pm–5pm window is the busiest, with 624 flights scheduled in it.
Across the year
United on SAT to IAH through the year
Delays peak in October, when the on-time rate falls to 72.2%. August is the strongest month at 92.0%. Moving a flexible trip across that boundary buys 20 points. September was the busiest month here, with 226 flights.
Across the week, Tuesday is the strongest day at 86.9% on time and Friday the weakest at 78.9%, a spread of 8 points.
Arrival by arrival
How late United on SAT to IAH runs when it is late
The 384 late arrivals split 164 under half an hour, 111 between 30 and 60 minutes, and 109 an hour or more.
- 15+ min early521 flights23.3%
- Within 15 min1,328 flights59.5%
- 15–29 min late164 flights7.3%
- 30–59 min late111 flights5.0%
- 1–2 hours late63 flights2.8%
- 2+ hours late46 flights2.1%
Scale runs 0% to 100%.
Share of 2,233 completed flights by arrival against schedule.
29 of 236 late departures made up the time and arrived on time, 12% of them. In the other direction, 177 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at IAH.
The worst days
Worst days for United on SAT to IAH
The latest arrival of the period was on 11 March 2026, 7 hours 52 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 March 2026 | 7 hours 52 minutes | Carrier |
| 7 March 2026 | 7 hours 1 minute | National Airspace System |
| 4 January 2026 | 6 hours 3 minutes | Carrier |
| 30 October 2025 | 5 hours 36 minutes | Carrier |
| 16 March 2026 | 5 hours 5 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
National Airspace System accounts for 51% of the 23,000 delay minutes carriers reported here, and the remaining four split what is left.
- 51%National Airspace System
- 25%Late-arriving aircraft
- 22%Carrier
- 2%Extreme weather
51% 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 11,000 minutes out of 23,000, against a national NAS share of 21%. The split is drawn from 22,614 reported delay minutes.
Cancellations are rare at 0.45%, below the national 1.89% 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 costs
Badly late arrivals are rare here: only 4.9% land an hour or more behind schedule, against 8.3% 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.
At 191 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 11am–2pm window matters as much as it does.
The return leg runs 83.0% on time across 2,247 flights, within half a point 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 2,245 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 United on SAT to IAH
Put together: the calendar is the biggest lever here, not the carrier or the hour. August runs 92.0% on time and October 72.2%, a swing of 20 points. If the dates move at all, move them out of October before you think about anything else. 2,233 completed flights over 12 months sit behind that.
Related
Where to go next
- SAT to IAH, every carrier
- United on IAH to SAT, the return leg
- SkyWest Airlines on SAT to IAH87.3%
- United Airlines network-wide record
- San Antonio International (SAT) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.