Best Time to Fly IAH to IAD: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
1,871 flights were scheduled from Houston (IAH) to Washington (IAD) in the last 12 months, and 81.4% of those that flew arrived on time, 3.7 points above the US average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Monday was the most reliable day (82% on time) and July the worst month (64%).
The cancellation rate was 0.4% (US average 1.8%).
IAH to IAD 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 | 81.4% | 62 min | 0.4% | 1,871 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to IAD
On-time arrival % by scheduled departure hour (local time), 3,714 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 2 | |
| 7am–8am | 92.4% | 0.7% | 729 |
| 9am–10am | 83.3% | 0.0% | 36 |
| 10am–11am | 87.5% | 0.0% | 88 |
| 12pm–1pm | 76.6% | 0.3% | 731 |
| 2pm–3pm | 84.2% | 0.0% | 82 |
| 3pm–4pm | 81.8% | 0.0% | 33 |
| 4pm–5pm | 75.2% | 0.8% | 612 |
| 5pm–6pm | 79.5% | 0.0% | 127 |
| 6pm–7pm | 76.3% | 1.1% | 703 |
| 7pm–8pm | 72.2% | 0.5% | 409 |
| 8pm–9pm | 76.1% | 0.0% | 159 |
| 9pm–10pm | Limited data | 3 | |
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 IAD
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% | +5.2 pts | 0.0% | 66 |
| Christmas & New Year (Dec 20 - Jan 3) | 75.0% | -7.7 pts | 0.0% | 148 |
| Summer peak (Jun 15 - Aug 15) | 66.3% | -16.4 pts | 0.8% | 651 |
| All other days | 82.7% | — | 0.6% | 2,849 |
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).