Houston (IAH) to Washington (IAD): On-Time Performance
Data through July 2026
When you fly IAH to IAD matters as much as anything else about the booking: the route swung from 93% on-time in September 2025 to just 57% in July 2024. Across the full period the route averages 79% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 74%), which matters most in the rough months.
- On-time
- 79%
- arrived <15 min late
- Avg delay
- 14 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 5.1
- last 12 months
- Duration
- 3h 5m
- scheduled
- Distance
- 1,190 mi
Monthly on-time trend
Best time to fly from IAH to IAD
Aim for departures around 7 a.m. (92% on-time); avoid 7 p.m. departures (71%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Mondaybest | 81% | 13 min |
| Tuesday | 81% | 14 min |
| Wednesday | 80% | 14 min |
| Thursday | 79% | 13 min |
| Friday | 77% | 17 min |
| Saturday | 75% | 17 min |
| Sunday | 78% | 14 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft35%
- Airline operations32%
- National airspace system22%
- Weather10%
Frequently asked questions
- How often are flights from IAH to IAD delayed?
- 21% of IAH–IAD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 14 minutes.
- What is the best time of day to fly from IAH to IAD?
- Departures around 7 a.m. have the best record (92% on-time), while departures around 7 p.m. have the worst (71%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from IAH to IAD?
- The scheduled IAH–IAD flight time averages 3h 5m over 1,190 miles. Actual arrival times vary — flights on this route land 15+ minutes late 21% of the time.
- How often are IAH to IAD flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from IAH to IAD?
- July 2024 was the roughest month in this dataset, with only 57% of arrivals on time. The best was September 2025 at 93%. If your dates are flexible, that 36-point gap is worth planning around.
Explore related pages
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Related guides
Based on 3,869 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.