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Route on-time record

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

Chicago (Chicago O'Hare International Airport) to Houston (George Bush Intercontinental Airport). 6,059 nonstop flights in Jun 2025 to May 2026, 75% arrived within 15 minutes and 1.4% were cancelled. The most reliable flight number was United 1898 at 5:48 AM.

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

ORD → IAH

Chicago to Houston: 6,059 nonstop flights a year

On time (12 months)

75%

Cancelled

1.4%

avg delay 20 min

Best time to leave

Before 9 AM

87% on time vs 62% 6 to 9 PM

Most reliable airline

United

78% chance on time

Check ORD to IAH fares

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 1898

    5:48 AM → 8:47 AM2h 59m nonstop

    Local times, typical schedule. Last flown 2026-04-29.

    89%

    chance on time

    On time (history)
    91%
    Cancelled
    0.0%
    Avg arrival delay
    4 min
    • Arrived on time 91% of the time (32 flights, Jun 2025 to May 2026).
    • Never cancelled in 32 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Limited track record · 32 flights

    Find United 1898 fares Opens this date on Aviasales

  2. #2 · United 1231

    7:30 AM → 10:37 AM3h 07m nonstop

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

    88%

    chance on time

    On time (history)
    90%
    Cancelled
    1.1%
    Avg arrival delay
    8 min
    • Arrived on time 90% of the time (176 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Moderate track record · 176 flights

    Find United 1231 fares Opens this date on Aviasales

  3. #3 · United 1464

    5:40 AM → 8:41 AM3h 01m nonstop

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

    87%

    chance on time

    On time (history)
    88%
    Cancelled
    0.0%
    Avg arrival delay
    3 min
    • Arrived on time 88% of the time (24 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).
    • Short track record (24 flights), so its score leans on the airline's record at this hour.

    Limited track record · 24 flights

    Find United 1464 fares Opens this date on Aviasales

  4. #4 · United 1799

    6:30 AM → 9:19 AM2h 49m 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: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 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 1799 fares Opens this date on Aviasales

  5. #5 · United 1448

    12:40 PM → 3:49 PM3h 04m nonstop

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

    85%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    14 min
    • Arrived on time 85% of the time (88 flights, Jun 2025 to May 2026).
    • Never cancelled in 88 scheduled flights.
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 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 · 88 flights

    Find United 1448 fares Opens this date on Aviasales

  6. #6 · United 535

    8:51 AM → 11:51 AM3h 00m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2320, 2231, 2225; its record covers all of them.

    84%

    chance on time

    On time (history)
    84%
    Cancelled
    0.7%
    Avg arrival delay
    11 min
    • Arrived on time 84% of the time (133 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Moderate track record · 133 flights

    Find United 535 fares Opens this date on Aviasales

  7. #7 · United 723

    10:30 AM → 1:29 PM2h 59m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2638; its record covers all of them.

    84%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    9 min
    • Arrived on time 85% of the time (201 flights, Jun 2025 to May 2026).
    • Never cancelled in 202 scheduled flights.
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 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 · 201 flights

    Find United 723 fares Opens this date on Aviasales

  8. #8 · United 2310

    5:30 AM → 8:18 AM2h 48m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2139; its record covers all of them.

    83%

    chance on time

    On time (history)
    78%
    Cancelled
    0.0%
    Avg arrival delay
    9 min
    • Arrived on time 78% of the time (32 flights, Jun 2025 to May 2026).
    • Never cancelled in 32 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Limited track record · 32 flights

    Find United 2310 fares Opens this date on Aviasales

  9. #9 · United 1954

    5:45 PM → 8:50 PM3h 05m nonstop

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

    83%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    1 min
    • Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
    • Departs inside ORD's trouble window: 44% of its 243 ground stops and delay programs started between 2 PM and 8 PM.
    • Short track record (11 flights), so its score leans on the airline's record at this hour.

    Limited track record · 11 flights

    Find United 1954 fares Opens this date on Aviasales

  10. #10 · Envoy 3521 · sold as American Eagle

    7:05 AM → 10:06 AM3h 01m nonstop

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

    79%

    chance on time

    On time (history)
    76%
    Cancelled
    0.0%
    Avg arrival delay
    13 min
    • Arrived on time 76% of the time (34 flights, Jun 2025 to May 2026).
    • Never cancelled in 34 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 62%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 44% of its 243 ground stops and delay programs started).

    Limited track record · 34 flights

    Find 7:05 AM flight fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • United Airlines78%

    3,973 flights · 78% on time as flown · 0.8% cancel

  • Frontier Airlines74%

    234 flights · 76% on time as flown · 2.1% cancel

  • Republic Airways (sold as American Eagle, Delta Connection or United Express)74%

    341 flights · 75% on time as flown · 2.1% cancel

  • Envoy Air (sold as American Eagle)71%

    384 flights · 74% on time as flown · 1.3% cancel

  • Spirit Airlines62%

    346 flights · 62% on time as flown · 3.9% cancel

  • American Airlines62%

    775 flights · 61% on time as flown · 2.4% cancel

On time by departure time

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

  • Before 9 AM87%

    1,433 flights · avg delay 10 min

  • 9 AM to noon81%

    862 flights · avg delay 13 min

  • Noon to 3 PM74%

    1,182 flights · avg delay 19 min

  • 3 to 6 PM70%

    1,052 flights · avg delay 23 min

  • 6 to 9 PM62%

    1,036 flights · avg delay 31 min

  • After 9 PM66%

    494 flights · avg delay 30 min

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

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.

J
75
F
85
M
78
A
77
M
70
J
71
J
64
A
76
S
85
O
84
N
83
D
80

What delays this route

  • Late-arriving aircraft40%
  • Airline (crew, maintenance, boarding)27%
  • Air traffic control and airport volume26%
  • 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

ORD to IAH questions

What time of day is best to fly ORD to IAH?
Before 9 AM: 87% of flights arrived on time, against 62% for departures 6 to 9 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 ORD to IAH?
United, with a season-adjusted 78% chance of operating and arriving on time over 3,973 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 ORD to IAH?
July (64% on time); the best was February (85%), 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 ORD

Live status: FAA delays and ground stops