Best Time to Fly IAH to DEN: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → Denver International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 82.0% of Houston (IAH) to Denver (DEN) flights arrived on time (4,715 scheduled flights). That is 4.3 points above the national average of 77.6%.
United Airlines was the most punctual of the 2 airlines on the route at 82.4%, while Frontier Airlines trailed at 79.8%.
October has been the best month (87% on time) and Monday the weakest day of the week (79%).
0.4% of flights were cancelled, versus 1.8% nationally.
IAH to DEN 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 | 82.4% | 67 min | 0.3% | 3,899 |
| Frontier Airlines | 79.8% | 74 min | 1.0% | 816 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to DEN
On-time arrival % by scheduled departure hour (local time), 9,303 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 92.1% | 0.3% | 633 |
| 6am–7am | 89.3% | 0.7% | 611 |
| 7am–8am | 87.9% | 0.8% | 750 |
| 8am–9am | 90.1% | 0.4% | 741 |
| 9am–10am | 82.4% | 0.4% | 452 |
| 10am–11am | 86.2% | 0.3% | 707 |
| 11am–12pm | 83.4% | 0.3% | 388 |
| 12pm–1pm | 86.1% | 0.5% | 754 |
| 1pm–2pm | 67.1% | 2.3% | 87 |
| 2pm–3pm | 77.4% | 0.5% | 659 |
| 3pm–4pm | 71.6% | 0.0% | 104 |
| 4pm–5pm | 68.2% | 0.1% | 763 |
| 5pm–6pm | 64.5% | 3.1% | 32 |
| 6pm–7pm | 64.7% | 0.9% | 789 |
| 7pm–8pm | 65.8% | 2.4% | 42 |
| 8pm–9pm | 73.3% | 0.2% | 786 |
| 9pm–10pm | 77.1% | 0.3% | 312 |
| 10pm–11pm | 80.2% | 0.6% | 687 |
| 11pm–12am | Limited data | 6 | |
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 DEN
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) | 85.1% | +3.4 pts | 0.0% | 168 |
| Christmas & New Year (Dec 20 - Jan 3) | 79.1% | -2.7 pts | 0.2% | 394 |
| Summer peak (Jun 15 - Aug 15) | 76.2% | -5.6 pts | 0.8% | 1,682 |
| All other days | 81.7% | — | 0.5% | 7,059 |
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).