Best Time to Fly IAH to SAT: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → San Antonio International
Data through July 2026 · Last updated October 18, 2026
2,406 flights were scheduled from Houston (IAH) to San Antonio (SAT) in the last 12 months, and 82.6% of those that flew arrived on time, 5.0 points above the US average of 77.6%.
Among 2 airlines, United Airlines led with 82.6% on time and SkyWest Airlines was last with 81.5%.
Over 24 months, Tuesday was the most reliable day (85% on time) and June the worst month (71%).
The cancellation rate was 0.4% (US average 1.8%).
IAH to SAT on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 82.6% | 58 min | 0.4% | 2,302 |
| SkyWest Airlines | 81.5% | 72 min | 1.0% | 104 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to SAT
On-time arrival % by scheduled departure hour (local time), 4,824 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | 94.3% | 0.9% | 690 |
| 9am–10am | 84.2% | 0.8% | 365 |
| 10am–11am | 82.9% | 0.0% | 164 |
| 11am–12pm | 89.8% | 0.0% | 158 |
| 12pm–1pm | 82.6% | 0.5% | 404 |
| 2pm–3pm | 81.2% | 0.2% | 639 |
| 4pm–5pm | 75.7% | 0.7% | 423 |
| 5pm–6pm | Limited data | 18 | |
| 6pm–7pm | 74.3% | 1.0% | 707 |
| 7pm–8pm | 65.7% | 4.1% | 73 |
| 8pm–9pm | 74.3% | 1.5% | 655 |
| 9pm–10pm | 78.0% | 0.9% | 426 |
| 10pm–11pm | 86.3% | 0.0% | 102 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAH to SAT
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 83.7% | +1.7 pts | 0.0% | 98 |
| Christmas & New Year (Dec 20 - Jan 3) | 83.7% | +1.6 pts | 1.9% | 162 |
| Summer peak (Jun 15 - Aug 15) | 73.8% | -8.2 pts | 1.5% | 752 |
| All other days | 82.0% | — | 0.7% | 3,812 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).