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ATIS Alerts Smart Flight Search

Find the flight least likely to be delayed

Beta

We rank real flight numbers by how often they flew and arrived on time over the last 12 months, adjusted for your travel month and departure time, then check nearby airports and calmer connections. US airlines and airports.

DEN → IAH

Denver to Houston: 4,632 nonstop flights a year

On time (12 months)

78%

Cancelled

0.3%

avg delay 15 min

Best time to leave

Before 9 AM

91% on time vs 71% noon to 3 PM

Most reliable airline

Frontier

79% chance on time

Check DEN to IAH fares

Lowest nonstop fare seen in the next two months: $62 (Frontier 2996 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. #1 · United 320

    5:00 AM → 8:30 AM2h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    95%

    chance on time

    On time (history)
    96%
    Cancelled
    0.5%
    Avg arrival delay
    3 min
    • Arrived on time 96% of the time (362 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 91% on time; Noon to 3 PM: 71%).
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).

    Strong track record · 362 flights

    Find United 320 fares Opens this date on Aviasales

  2. #2 · United 1720

    7:45 AM → 11:15 AM2h 30m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    89%

    chance on time

    On time (history)
    89%
    Cancelled
    0.3%
    Avg arrival delay
    5 min
    • Arrived on time 89% of the time (364 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 91% on time; Noon to 3 PM: 71%).
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).

    Strong track record · 364 flights

    Find United 1720 fares Opens this date on Aviasales

  3. #3 · United 788

    6:17 AM → 9:50 AM2h 33m nonstop

    Local times, typical schedule. Last flown 2026-03-28.

    87%

    chance on time

    On time (history)
    94%
    Cancelled
    0.0%
    Avg arrival delay
    11 min
    • Arrived on time 94% of the time (18 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 91% on time; Noon to 3 PM: 71%).
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
    • Short track record (18 flights), so its score leans on the airline's record at this hour.

    Limited track record · 18 flights

    Find United 788 fares Opens this date on Aviasales

  4. #4 · Frontier 3206

    5:15 AM → 1:44 PM2h 43m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    86%

    chance on time

    On time (history)
    85%
    Cancelled
    0.3%
    Avg arrival delay
    8 min
    • Arrived on time 85% of the time (313 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 91% on time; Noon to 3 PM: 71%).
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
    • Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.

    Strong track record · 313 flights

    Find Frontier 3206 fares Opens this date on Aviasales

  5. #5 · United 1915

    9:50 AM → 1:28 PM2h 38m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    83%

    chance on time

    On time (history)
    88%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 88% of the time (73 flights, Jun 2025 to May 2026).
    • Never cancelled in 74 scheduled flights.
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
    • Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.

    Moderate track record · 73 flights

    Find United 1915 fares Opens this date on Aviasales

  6. #6 · Frontier 4856

    6:25 PM → 10:01 PM2h 36m nonstop

    Local times, typical schedule. Last flown 2026-04-28.

    79%

    chance on time

    On time (history)
    83%
    Cancelled
    0.0%
    Avg arrival delay
    10 min
    • Arrived on time 83% of the time (36 flights, Jun 2025 to May 2026).
    • Never cancelled in 36 scheduled flights.
    • Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
    • Short track record (36 flights), so its score leans on the airline's record at this hour.

    Limited track record · 36 flights

    Find Frontier 4856 fares Opens this date on Aviasales

  7. #7 · United 1253

    9:10 PM → 12:41 AM2h 31m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 568; its record covers all of them.

    77%

    chance on time

    On time (history)
    79%
    Cancelled
    5.7%
    Avg arrival delay
    15 min
    • Arrived on time 79% of the time (33 flights, Jun 2025 to May 2026).
    • Cancelled 5.7% of the time (2 of 35).
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
    • Short track record (33 flights), so its score leans on the airline's record at this hour.

    Limited track record · 33 flights

    Find United 1253 fares Opens this date on Aviasales

  8. #8 · United 2841

    10:07 AM → 1:40 PM2h 33m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 423; its record covers all of them.

    77%

    chance on time

    On time (history)
    74%
    Cancelled
    0.0%
    Avg arrival delay
    30 min
    • Arrived on time 74% of the time (35 flights, Jun 2025 to May 2026).
    • Never cancelled in 35 scheduled flights.
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
    • Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.

    Limited track record · 35 flights

    Find United 2841 fares Opens this date on Aviasales

  9. #9 · United 2419

    8:23 PM → 11:59 PM2h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    77%

    chance on time

    On time (history)
    78%
    Cancelled
    0.0%
    Avg arrival delay
    19 min
    • Arrived on time 78% of the time (338 flights, Jun 2025 to May 2026).
    • Never cancelled in 338 scheduled flights.
    • Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).

    Strong track record · 338 flights

    Find United 2419 fares Opens this date on Aviasales

  10. #10 · Frontier 3228

    5:27 PM → 9:10 PM2h 43m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    76%

    chance on time

    On time (history)
    84%
    Cancelled
    0.0%
    Avg arrival delay
    13 min
    • Arrived on time 84% of the time (67 flights, Jun 2025 to May 2026).
    • Never cancelled in 67 scheduled flights.
    • Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.

    Moderate track record · 67 flights

    Find Frontier 3228 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Frontier Airlines79%

    778 flights · 79% on time as flown · 0.2% cancel

  • United Airlines78%

    3,854 flights · 78% 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%

    1,004 flights · avg delay 5 min

  • 9 AM to noon80%

    779 flights · avg delay 14 min

  • Noon to 3 PM71%

    400 flights · avg delay 20 min

  • 3 to 6 PM71%

    1,187 flights · avg delay 20 min

  • 6 to 9 PM74%

    1,050 flights · avg delay 19 min

  • After 9 PM80%

    212 flights · avg delay 12 min

Best day: Wednesday (80%). Worst: Friday (74%).

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