Best Time to Fly ATL to IAH: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → George Bush Intercontinental/Houston
Data through July 2026 · Last updated October 18, 2026
4,926 flights were scheduled from Atlanta (ATL) to Houston (IAH) in the last 12 months, and 76.5% of those that flew arrived on time, 1.2 points below the US average of 77.6%.
Among 4 airlines, United Airlines led with 84.9% on time and Spirit Airlines was last with 65.7%.
Over 24 months, Wednesday was the most reliable day (79% on time) and June the worst month (65%).
The cancellation rate was 1.9% (US average 1.8%).
ATL 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 | 84.9% | 71 min | 0.8% | 1,261 |
| Delta Air Lines | 75.6% | 56 min | 1.9% | 2,521 |
| Frontier Airlines | 70.1% | 82 min | 1.9% | 798 |
| Spirit Airlines | 65.7% | 79 min | 5.0% | 342 |
| SkyWest Airlines | Limited data | 4 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to IAH
On-time arrival % by scheduled departure hour (local time), 9,467 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 21 | |
| 6am–7am | 83.1% | 1.4% | 277 |
| 7am–8am | 83.7% | 2.0% | 1,286 |
| 8am–9am | 78.8% | 2.1% | 241 |
| 9am–10am | 82.2% | 3.0% | 876 |
| 10am–11am | 80.6% | 2.0% | 297 |
| 11am–12pm | 86.6% | 0.6% | 720 |
| 12pm–1pm | 80.3% | 0.2% | 499 |
| 1pm–2pm | 78.7% | 1.5% | 342 |
| 2pm–3pm | 72.0% | 1.5% | 520 |
| 3pm–4pm | 72.2% | 0.6% | 695 |
| 4pm–5pm | 67.3% | 1.9% | 633 |
| 5pm–6pm | 66.2% | 0.6% | 468 |
| 6pm–7pm | 63.6% | 1.0% | 391 |
| 7pm–8pm | 72.0% | 2.5% | 731 |
| 8pm–9pm | 61.9% | 1.5% | 272 |
| 9pm–10pm | 58.4% | 2.9% | 453 |
| 10pm–11pm | 71.7% | 2.8% | 745 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ATL 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) | 71.6% | -5.6 pts | 0.5% | 198 |
| Christmas & New Year (Dec 20 - Jan 3) | 72.1% | -5.0 pts | 2.6% | 304 |
| Summer peak (Jun 15 - Aug 15) | 67.6% | -9.6 pts | 2.5% | 1,669 |
| All other days | 77.1% | — | 1.6% | 7,296 |
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).