Best Time to Fly STL to IAH: On-Time Stats by Hour & Airline
St Louis Lambert International → George Bush Intercontinental/Houston
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 80.6% of St. Louis (STL) to Houston (IAH) flights arrived on time (423 scheduled flights). That is 3.0 points above the national average of 77.6%.
Among 2 airlines, United Airlines led with 83.8% on time and SkyWest Airlines was last with 64.2%.
Over 24 months, Tuesday was the most reliable day (84% on time) and July the worst month (63%).
The cancellation rate was 1.2% (US average 1.8%).
STL 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 | 83.8% | 56 min | 1.4% | 356 |
| SkyWest Airlines | 64.2% | 85 min | 0.0% | 67 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to IAH
On-time arrival % by scheduled departure hour (local time), 1,096 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 84.6% | 1.6% | 514 |
| 7am–8am | Limited data | 1 | |
| 8am–9am | 83.5% | 1.9% | 156 |
| 10am–11am | Limited data | 1 | |
| 11am–12pm | 68.4% | 0.0% | 38 |
| 2pm–3pm | 64.0% | 0.0% | 50 |
| 3pm–4pm | Limited data | 1 | |
| 4pm–5pm | 72.4% | 1.6% | 185 |
| 5pm–6pm | 63.4% | 0.0% | 112 |
| 6pm–7pm | 71.0% | 0.0% | 38 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on STL 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) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 30 | ||
| Summer peak (Jun 15 - Aug 15) | 66.7% | -13.3 pts | 0.0% | 148 |
| All other days | 80.0% | — | 1.5% | 892 |
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).