Best Time to Fly SEA to IAH: On-Time Stats by Hour & Airline
Seattle/Tacoma International → George Bush Intercontinental/Houston
Data through July 2026 · Last updated October 18, 2026
2,090 flights were scheduled from Seattle (SEA) to Houston (IAH) in the last 12 months, and 82.3% of those that flew arrived on time, 4.7 points above the US average of 77.6%.
Among 2 airlines, United Airlines led with 86.4% on time and Alaska Airlines was last with 76.3%.
Over 24 months, Wednesday was the most reliable day (84% on time) and August the worst month (72%).
The cancellation rate was 0.4% (US average 1.8%).
SEA 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 | 86.4% | 78 min | 0.3% | 1,238 |
| Alaska Airlines | 76.3% | 46 min | 0.6% | 852 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SEA to IAH
On-time arrival % by scheduled departure hour (local time), 4,185 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 86.7% | 1.2% | 161 |
| 6am–7am | 92.9% | 2.0% | 101 |
| 7am–8am | 88.8% | 0.5% | 628 |
| 9am–10am | 89.3% | 0.0% | 56 |
| 10am–11am | 79.3% | 0.7% | 298 |
| 11am–12pm | 65.2% | 0.8% | 587 |
| 12pm–1pm | 79.2% | 0.8% | 133 |
| 1pm–2pm | 81.9% | 0.9% | 228 |
| 2pm–3pm | 81.9% | 0.0% | 178 |
| 3pm–4pm | 97.3% | 0.0% | 38 |
| 4pm–5pm | Limited data | 23 | |
| 5pm–6pm | 77.5% | 0.8% | 801 |
| 6pm–7pm | Limited data | 1 | |
| 10pm–11pm | Limited data | 25 | |
| 11pm–12am | 80.8% | 1.0% | 927 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SEA 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) | 87.9% | +5.6 pts | 0.0% | 66 |
| Christmas & New Year (Dec 20 - Jan 3) | 77.9% | -4.4 pts | 0.6% | 165 |
| Summer peak (Jun 15 - Aug 15) | 72.1% | -10.2 pts | 1.7% | 943 |
| All other days | 82.3% | — | 0.5% | 3,011 |
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).