Denver (DEN) to Houston (IAH): On-Time Performance
Data through July 2026
The calendar drives reliability on DEN–IAH. October 2024 flights landed on schedule 90% of the time, but July 2025 dropped to 56% — a gap of 34 points. Across the full period the route averages 78% on-time against a national 78%. Morning departures also hold up better than evening ones (86% vs 72%), which matters most in the rough months.
- On-time
- 78%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 13
- last 12 months
- Duration
- 2h 30m
- scheduled
- Distance
- 861 mi
Best airline from DEN to IAH
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 78% | 15 min | 0.6% | 8,102 |
| Frontier Airlines | 76% | 16 min | 1.0% | 1,593 |
| Southwest Airlines | 75% | 17 min | 2.7% | 75 |
Monthly on-time trend
Best time to fly from DEN to IAH
Aim for departures around 5 a.m. (94% on-time); avoid 6 p.m. departures (67%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 76% | 16 min |
| Tuesdaybest | 80% | 14 min |
| Wednesday | 78% | 15 min |
| Thursday | 76% | 15 min |
| Friday | 76% | 16 min |
| Saturday | 79% | 14 min |
| Sunday | 77% | 17 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft40%
- Airline operations26%
- National airspace system32%
- Weather3%
Frequently asked questions
- How often are flights from DEN to IAH delayed?
- 23% of DEN–IAH flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 15 minutes.
- Which airline is most reliable from DEN to IAH?
- United Airlines has the best on-time record on this route at 78%, based on 8,102 flights. 3 airlines flew DEN–IAH frequently enough to compare in this period.
- What is the best time of day to fly from DEN to IAH?
- Departures around 5 a.m. have the best record (94% on-time), while departures around 6 p.m. have the worst (67%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DEN to IAH?
- The scheduled DEN–IAH flight time averages 2h 30m over 861 miles. Actual arrival times vary — flights on this route land 15+ minutes late 23% of the time.
- How often are DEN to IAH flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from DEN to IAH?
- July 2025 was the roughest month in this dataset, with only 56% of arrivals on time. The best was October 2024 at 90%. If your dates are flexible, that 34-point gap is worth planning around.
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Based on 9,770 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.