Route on-time record

IAH to DEN: most on-time flights and the best time to fly

Houston (George Bush Intercontinental Airport) to Denver (Denver International Airport). 4,632 nonstop flights in Jun 2025 to May 2026, 81% arrived within 15 minutes and 0.3% were cancelled. The most reliable flight number was United 1800 at 8:08 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

IAH → DEN

Houston to Denver: 4,632 nonstop flights a year

On time (12 months)

81%

Cancelled

0.3%

avg delay 14 min

Best time to leave

Before 9 AM

91% on time vs 67% 3 to 6 PM

Most reliable airline

United

81% chance on time

Check IAH to DEN fares

Lowest nonstop fare seen in the next two months: $61 (Frontier 3205 on 2026-10-29). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

#1 · United 1800
8:08 AM → 9:50 AM2h 42m nonstop
Local times, typical schedule. Last flown 2026-05-20. Same departure also flew as United 1544; its record covers all of them.
94%
chance on time
On time (history)
98%
Cancelled
0.0%
Avg arrival delay
1 min
- Arrived on time 98% of the time (53 flights, Jun 2025 to May 2026).
- Never cancelled in 53 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Limited track record · 53 flights
Find United 1800 fares Opens this date on Aviasales
#2 · United 1874
5:00 AM → 6:40 AM2h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
92%
chance on time
On time (history)
93%
Cancelled
0.0%
Avg arrival delay
8 min
- Arrived on time 93% of the time (29 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (29 flights), so its score leans on the airline's record at this hour.
Limited track record · 29 flights
Find United 1874 fares Opens this date on Aviasales
#3 · United 2433
6:40 AM → 8:20 AM2h 40m nonstop
Local times, typical schedule. Last flown 2026-03-28.
91%
chance on time
On time (history)
92%
Cancelled
0.0%
Avg arrival delay
4 min
- Arrived on time 92% of the time (300 flights, Jun 2025 to May 2026).
- Never cancelled in 300 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 300 flights
Find United 2433 fares Opens this date on Aviasales
#4 · United 2643
7:00 AM → 8:38 AM2h 38m nonstop
Local times, typical schedule. Last flown 2026-05-31.
90%
chance on time
On time (history)
94%
Cancelled
0.0%
Avg arrival delay
3 min
- Arrived on time 94% of the time (64 flights, Jun 2025 to May 2026).
- Never cancelled in 64 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Moderate track record · 64 flights
Find United 2643 fares Opens this date on Aviasales
#5 · United 2802
8:30 AM → 10:05 AM2h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31.
89%
chance on time
On time (history)
91%
Cancelled
0.0%
Avg arrival delay
3 min
- Arrived on time 91% of the time (11 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (11 flights), so its score leans on the airline's record at this hour.
Limited track record · 11 flights
Find United 2802 fares Opens this date on Aviasales
#6 · Frontier 3229
6:45 AM → 8:26 AM2h 41m nonstop
Local times, typical schedule. Last flown 2026-05-31.
87%
chance on time
On time (history)
88%
Cancelled
0.3%
Avg arrival delay
15 min
- Arrived on time 88% of the time (355 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 355 flights
Find Frontier 3229 fares Opens this date on Aviasales
#7 · United 1066
10:15 PM → 11:57 PM2h 42m nonstop
Local times, typical schedule. Last flown 2026-05-31.
87%
chance on time
On time (history)
91%
Cancelled
0.7%
Avg arrival delay
6 min
- Arrived on time 91% of the time (144 flights, Jun 2025 to May 2026).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Moderate track record · 144 flights
Find United 1066 fares Opens this date on Aviasales
#8 · United 2168
12:48 PM → 2:33 PM2h 45m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
89%
Cancelled
0.0%
Avg arrival delay
7 min
- Arrived on time 89% of the time (88 flights, Jun 2025 to May 2026).
- Never cancelled in 88 scheduled flights.
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Moderate track record · 88 flights
Find United 2168 fares Opens this date on Aviasales
#9 · United 1575
7:20 AM → 8:55 AM2h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
82%
Cancelled
0.0%
Avg arrival delay
7 min
- Arrived on time 82% of the time (11 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 67%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (11 flights), so its score leans on the airline's record at this hour.
Limited track record · 11 flights
Find United 1575 fares Opens this date on Aviasales
#10 · Frontier 3205
10:05 PM → 11:58 PM2h 53m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
On time (history)
91%
Cancelled
0.0%
Avg arrival delay
6 min
- Arrived on time 91% of the time (35 flights, Jun 2025 to May 2026).
- Never cancelled in 35 scheduled flights.
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (35 flights), so its score leans on the airline's record at this hour.
Limited track record · 35 flights
Find Frontier 3205 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

United Airlines81%
3,854 flights · 81% on time as flown · 0.3% cancel
Frontier Airlines81%
778 flights · 81% on time as flown · 0.3% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

Before 9 AM91%
1,298 flights · avg delay 8 min
9 AM to noon86%
849 flights · avg delay 10 min
Noon to 3 PM80%
722 flights · avg delay 17 min
3 to 6 PM67%
462 flights · avg delay 25 min
6 to 9 PM68%
769 flights · avg delay 21 min
After 9 PM81%
532 flights · avg delay 14 min

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

What delays this route

Late-arriving aircraft37%
Airline (crew, maintenance, boarding)28%
Air traffic control and airport volume27%
Severe weather7%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

IAH to DEN questions

What time of day is best to fly IAH to DEN?: Before 9 AM: 91% of flights arrived on time, against 67% for departures 3 to 6 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from IAH to DEN?: United, with a season-adjusted 81% chance of operating and arriving on time over 3,854 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on IAH to DEN?: June (65% on time); the best was October (86%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?: No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from IAH

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