Best Time to Fly SFO to IAH: On-Time Stats by Hour & Airline
San Francisco International → George Bush Intercontinental/Houston
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 84.3% of San Francisco (SFO) to Houston (IAH) flights arrived on time (3,598 scheduled flights). That is 6.7 points above the national average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
September has been the best month (92% on time) and Monday the weakest day of the week (82%).
0.3% of flights were cancelled, versus 1.8% nationally.
SFO to IAH 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 | 84.3% | 52 min | 0.3% | 3,598 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SFO to IAH
On-time arrival % by scheduled departure hour (local time), 6,917 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | 86.9% | 0.3% | 654 |
| 5am–6am | 96.2% | 0.6% | 726 |
| 6am–7am | Limited data | 3 | |
| 7am–8am | 94.9% | 0.4% | 730 |
| 8am–9am | 87.4% | 0.4% | 225 |
| 9am–10am | 82.5% | 1.0% | 505 |
| 10am–11am | 70.2% | 0.0% | 276 |
| 11am–12pm | 72.5% | 0.9% | 454 |
| 12pm–1pm | 76.2% | 0.0% | 251 |
| 1pm–2pm | 78.2% | 0.2% | 479 |
| 2pm–3pm | 82.3% | 0.3% | 723 |
| 3pm–4pm | Limited data | 7 | |
| 4pm–5pm | 82.8% | 0.0% | 512 |
| 5pm–6pm | Limited data | 21 | |
| 6pm–7pm | 81.8% | 1.0% | 412 |
| 7pm–8pm | 88.2% | 0.0% | 203 |
| 10pm–11pm | Limited data | 5 | |
| 11pm–12am | 84.3% | 0.4% | 731 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SFO to IAH
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) | 88.5% | +2.4 pts | 0.0% | 131 |
| Christmas & New Year (Dec 20 - Jan 3) | 68.7% | -17.4 pts | 1.4% | 285 |
| Summer peak (Jun 15 - Aug 15) | 80.5% | -5.6 pts | 0.2% | 1,195 |
| All other days | 86.1% | — | 0.4% | 5,306 |
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).