Best Time to Fly IAD to IAH: On-Time Stats by Hour & Airline
Washington Dulles International → George Bush Intercontinental/Houston
Data through July 2026 · Last updated October 18, 2026
1,873 flights were scheduled from Washington (IAD) to Houston (IAH) in the last 12 months, and 84.2% of those that flew arrived on time, 6.5 points above the US average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
September has been the best month (90% on time) and Saturday the weakest day of the week (80%).
0.4% of flights were cancelled, versus 1.8% nationally.
IAD 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 | 84.2% | 68 min | 0.4% | 1,873 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to IAH
On-time arrival % by scheduled departure hour (local time), 3,713 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 91.4% | 0.3% | 710 |
| 7am–8am | Limited data | 2 | |
| 8am–9am | 88.3% | 0.7% | 730 |
| 10am–11am | 83.9% | 0.0% | 31 |
| 11am–12pm | 94.6% | 0.0% | 37 |
| 12pm–1pm | 83.8% | 0.8% | 669 |
| 1pm–2pm | 96.4% | 1.8% | 57 |
| 2pm–3pm | 70.5% | 0.0% | 45 |
| 3pm–4pm | Limited data | 21 | |
| 4pm–5pm | 61.4% | 1.0% | 102 |
| 5pm–6pm | 67.0% | 0.4% | 719 |
| 6pm–7pm | Limited data | 12 | |
| 8pm–9pm | Limited data | 1 | |
| 10pm–11pm | 81.5% | 1.2% | 577 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAD 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) | 84.8% | +1.2 pts | 0.0% | 66 |
| Christmas & New Year (Dec 20 - Jan 3) | 83.7% | +0.0 pts | 0.7% | 148 |
| Summer peak (Jun 15 - Aug 15) | 74.2% | -9.5 pts | 0.8% | 652 |
| All other days | 83.7% | — | 0.6% | 2,847 |
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).