FlightRecord

Chicago (ORD) to Houston (IAH): On-Time Performance

Data through May 2026

When you fly ORD to IAH matters as much as anything else about the booking: the route swung from 89% on-time in October 2024 to just 57% in July 2024. Across the full period the route averages 76% on-time against a national 78%. Morning departures also hold up better than evening ones (84% vs 68%), which matters most in the rough months.

On-time
76%
arrived <15 min late
Avg delay
18 min
completed flights
Cancelled
1.4%
Flights/day
17
last 12 months
Duration
2h 56m
scheduled
Distance
925 mi

Best airline from ORD to IAH

6 airlines flew this route regularly between 2024-06 and 2026-05.

AirlineOn-timeAvg delayCancelledFlights
United Airlinesmost reliable79%14 min0.9%7,776
Republic Airways74%19 min2.5%524
Envoy Air74%17 min1.5%473
Frontier Airlines74%23 min2.4%420
Spirit Airlines67%29 min2.7%956
American Airlines67%28 min2.3%1,512

Monthly on-time trend

Monthly on-time percentage for ORD to IAH flights50%75%100%June 2024: 73% on-time (488 flights)73Jun 2024July 2024: 57% on-time (495 flights)57August 2024: 75% on-time (502 flights)75September 2024: 85% on-time (471 flights)85Sep 2024October 2024: 89% on-time (473 flights)89November 2024: 84% on-time (455 flights)84December 2024: 76% on-time (477 flights)76Dec 2024January 2025: 75% on-time (457 flights)75February 2025: 79% on-time (390 flights)79March 2025: 82% on-time (461 flights)82Mar 2025April 2025: 78% on-time (434 flights)78May 2025: 75% on-time (506 flights)75June 2025: 65% on-time (507 flights)65Jun 2025July 2025: 63% on-time (516 flights)63August 2025: 72% on-time (531 flights)72September 2025: 84% on-time (532 flights)84Sep 2025October 2025: 79% on-time (518 flights)79November 2025: 78% on-time (467 flights)78December 2025: 74% on-time (512 flights)74Dec 2025January 2026: 79% on-time (468 flights)79February 2026: 86% on-time (433 flights)86March 2026: 72% on-time (512 flights)72Mar 2026April 2026: 71% on-time (526 flights)71May 2026: 74% on-time (537 flights)74

Best time to fly from ORD to IAH

Aim for departures around 5 a.m. (90% on-time); avoid 7 p.m. departures (63%).

On-time percentage by scheduled departure hour, ORD to IAH5 a.m.: 90% on-time (473 flights)56 a.m.: 88% on-time (705 flights)67 a.m.: 85% on-time (979 flights)78 a.m.: 85% on-time (694 flights)89 a.m.: 78% on-time (737 flights)910 a.m.: 82% on-time (890 flights)1011 a.m.: 86% on-time (55 flights)1112 p.m.: 83% on-time (782 flights)121 p.m.: 71% on-time (554 flights)132 p.m.: 71% on-time (1,032 flights)143 p.m.: 69% on-time (617 flights)154 p.m.: 68% on-time (635 flights)165 p.m.: 75% on-time (525 flights)176 p.m.: 73% on-time (547 flights)187 p.m.: 63% on-time (466 flights)198 p.m.: 64% on-time (1,020 flights)209 p.m.: 67% on-time (934 flights)21scheduled departure hour

By day of week

DayOn-timeAvg delay
Monday76%20 min
Tuesdaybest79%15 min
Wednesday78%17 min
Thursday76%17 min
Friday72%20 min
Saturday77%16 min
Sunday74%19 min

What causes delays on this route

Share of total delay minutes by cause, as reported by carriers to the US DOT.

  • Late-arriving aircraft39%
  • Airline operations27%
  • National airspace system28%
  • Weather6%

Frequently asked questions

How often are flights from ORD to IAH delayed?
24% of ORD–IAH 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 18 minutes.
Which airline is most reliable from ORD to IAH?
United Airlines has the best on-time record on this route at 79%, based on 7,776 flights. 6 airlines flew ORD–IAH frequently enough to compare in this period.
What is the best time of day to fly from ORD to IAH?
Departures around 5 a.m. have the best record (90% on-time), while departures around 7 p.m. have the worst (63%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
How long is the flight from ORD to IAH?
The scheduled ORD–IAH flight time averages 2h 56m over 925 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
How often are ORD to IAH flights cancelled?
1.4% 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 ORD to IAH?
July 2024 was the roughest month in this dataset, with only 57% of arrivals on time. The best was October 2024 at 89%. If your dates are flexible, that 32-point gap is worth planning around.

Based on 11,668 flights, 2024-062026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.