George Bush Intercontinental/Houston (IAH) Delays and On-Time Departures
Houston, TX · ranked 220th of 333 airports for on-time departures
Data through July 2026 · Last updated October 18, 2026
79.0% of the 119,020 flights scheduled to depart Houston (IAH) in the last 12 months left on time, 1.5 points above the US average of 77.4%.
That ranks 220th of 333 US airports tracked on this site, with 1.1% of departures cancelled.
Among airlines at Houston (IAH), United Airlines left on time most often (80.4%).
Over 24 months, Tuesday was the most reliable day (82% on time) and June the worst month (68%).
Best time of day to fly out of Houston (IAH)
On-time departure % by scheduled departure hour (local time), last 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | Limited data | 7 | |
| 5am–6am | 91.7% | 1.6% | 6,343 |
| 6am–7am | 90.2% | 1.8% | 9,115 |
| 7am–8am | 90.4% | 1.0% | 22,934 |
| 8am–9am | 87.5% | 1.3% | 6,912 |
| 9am–10am | 83.9% | 1.0% | 17,015 |
| 10am–11am | 81.1% | 0.9% | 10,238 |
| 11am–12pm | 79.9% | 1.2% | 9,380 |
| 12pm–1pm | 80.8% | 0.9% | 24,308 |
| 1pm–2pm | 72.2% | 1.5% | 4,324 |
| 2pm–3pm | 76.3% | 1.0% | 19,970 |
| 3pm–4pm | 73.2% | 0.7% | 4,212 |
| 4pm–5pm | 74.6% | 1.5% | 18,945 |
| 5pm–6pm | 69.3% | 1.6% | 6,954 |
| 6pm–7pm | 70.6% | 1.4% | 29,826 |
| 7pm–8pm | 67.1% | 1.4% | 11,854 |
| 8pm–9pm | 71.3% | 1.2% | 23,190 |
| 9pm–10pm | 74.3% | 1.7% | 6,447 |
| 10pm–11pm | 77.0% | 1.3% | 3,477 |
| 11pm–12am | 81.9% | 1.4% | 368 |
Airlines at IAH ranked by on-time departures
Last 12 months. Airlines with fewer than 30 departures are marked “limited data”.
| Airline | On-time departures | On-time arrivals | Cancelled | Departures |
|---|---|---|---|---|
| United Airlines | 80.4% | 80.0% | 0.6% | 74,382 |
| Delta Air Lines | 80.1% | 80.8% | 1.9% | 8,388 |
| SkyWest Airlines | 78.6% | 77.1% | 1.0% | 14,030 |
| Alaska Airlines | 77.4% | 79.3% | 0.8% | 1,205 |
| Envoy Air | 77.3% | 77.0% | 1.9% | 1,285 |
| Republic Airways | 77.3% | 74.3% | 4.2% | 913 |
| American Airlines | 75.1% | 76.8% | 2.5% | 7,876 |
| Spirit Airlines | 74.0% | 74.8% | 2.9% | 4,744 |
| Frontier Airlines | 72.9% | 70.3% | 2.2% | 5,062 |
| PSA Airlines | 72.2% | 68.6% | 5.6% | 463 |
| JetBlue | 52.6% | 53.0% | 3.9% | 672 |
80%+ good 70–79.9% fair <70% poor
Best day to fly out of IAH
On-time departures by day, 24 months.
Best month to fly out of IAH
On-time departures by month, 24 months.
Holiday travel at Houston (IAH)
On-time departures during holiday periods compared with all other days, last 24 months.
| Period | On-time departures | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 80.3% | +0.3 pts | 0.4% | 4,550 |
| Christmas & New Year (Dec 20 - Jan 3) | 73.3% | -6.7 pts | 1.7% | 9,163 |
| Summer peak (Jun 15 - Aug 15) | 70.6% | -9.4 pts | 1.7% | 41,237 |
| All other days | 80.0% | — | 1.1% | 180,869 |
Monthly on-time departure trend at IAH
On-time departure % each month, with the 12-month US average for reference.
Routes from Houston (IAH)
Every route from IAH with its own page, by number of flights (last 12 months, on-time arrivals).