Best Time to Fly IAH to ATL: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → Hartsfield-Jackson Atlanta International
Data through July 2026 · Last updated October 18, 2026
4,919 flights were scheduled from Houston (IAH) to Atlanta (ATL) in the last 12 months, and 77.1% of those that flew arrived on time, in line with the US average of 77.6%.
Among 4 airlines, United Airlines led with 81.0% on time and Frontier Airlines was last with 62.1%.
Over 24 months, Wednesday was the most reliable day (82% on time) and June the worst month (66%).
The cancellation rate was 2.0% (US average 1.8%).
IAH to ATL 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 | 81.0% | 62 min | 0.6% | 1,263 |
| Delta Air Lines | 80.1% | 67 min | 2.1% | 2,520 |
| Spirit Airlines | 75.5% | 59 min | 4.8% | 334 |
| Frontier Airlines | 62.1% | 69 min | 2.9% | 798 |
| SkyWest Airlines | Limited data | 4 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to ATL
On-time arrival % by scheduled departure hour (local time), 9,463 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 86.2% | 4.0% | 597 |
| 6am–7am | 79.5% | 2.3% | 780 |
| 7am–8am | 88.8% | 0.9% | 1,374 |
| 8am–9am | 83.5% | 0.8% | 239 |
| 9am–10am | 81.4% | 2.4% | 639 |
| 10am–11am | 76.6% | 2.7% | 111 |
| 11am–12pm | 80.6% | 2.0% | 732 |
| 12pm–1pm | 76.9% | 0.9% | 562 |
| 1pm–2pm | 75.3% | 0.3% | 325 |
| 2pm–3pm | 74.9% | 0.6% | 896 |
| 3pm–4pm | 73.7% | 1.9% | 373 |
| 4pm–5pm | 64.8% | 1.4% | 514 |
| 5pm–6pm | 64.7% | 2.0% | 460 |
| 6pm–7pm | 69.0% | 2.1% | 1,209 |
| 7pm–8pm | 66.4% | 3.4% | 148 |
| 8pm–9pm | 70.7% | 2.9% | 456 |
| 9pm–10pm | 58.1% | 8.8% | 34 |
| 10pm–11pm | Limited data | 11 | |
| 11pm–12am | 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 ATL
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) | 78.3% | -0.2 pts | 1.5% | 197 |
| Christmas & New Year (Dec 20 - Jan 3) | 71.7% | -6.8 pts | 2.3% | 304 |
| Summer peak (Jun 15 - Aug 15) | 71.3% | -7.2 pts | 2.5% | 1,663 |
| All other days | 78.5% | — | 1.6% | 7,299 |
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).