Houston (IAH) to Denver (DEN): On-Time Performance
Data through May 2026
Houston (IAH) to Denver (DEN) effectively runs on two schedules. In October 2024, 91% of arrivals were on time; in July 2024 that fell to 67% — a 23-point seasonal swing. Across the full period the route averages 80% on-time against a national 78%. Morning departures also hold up better than evening ones (87% vs 72%), which matters most in the rough months.
- On-time
- 80%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 13
- last 12 months
- Duration
- 2h 40m
- scheduled
- Distance
- 861 mi
Best airline from IAH to DEN
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 81% | 14 min | 0.6% | 7,717 |
| Frontier Airlines | 75% | 20 min | 1.3% | 1,494 |
| Southwest Airlines | 66% | 22 min | 1.4% | 139 |
Monthly on-time trend
Best time to fly from IAH to DEN
Aim for departures around 5 a.m. (92% on-time); avoid 7 p.m. departures (60%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 78% | 18 min |
| Tuesdaybest | 82% | 14 min |
| Wednesday | 80% | 16 min |
| Thursday | 80% | 14 min |
| Friday | 79% | 16 min |
| Saturday | 80% | 15 min |
| Sunday | 78% | 15 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft37%
- Airline operations32%
- National airspace system25%
- Weather7%
Frequently asked questions
- How often are flights from IAH to DEN delayed?
- 20% of IAH–DEN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 15 minutes.
- Which airline is most reliable from IAH to DEN?
- United Airlines has the best on-time record on this route at 81%, based on 7,717 flights. 3 airlines flew IAH–DEN frequently enough to compare in this period.
- What is the best time of day to fly from IAH to DEN?
- Departures around 5 a.m. have the best record (92% on-time), while departures around 7 p.m. have the worst (60%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from IAH to DEN?
- The scheduled IAH–DEN flight time averages 2h 40m over 861 miles. Actual arrival times vary — flights on this route land 15+ minutes late 20% of the time.
- How often are IAH to DEN flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from IAH to DEN?
- July 2024 was the roughest month in this dataset, with only 67% of arrivals on time. The best was October 2024 at 91%. If your dates are flexible, that 23-point gap is worth planning around.
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Based on 9,350 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.