PlainFlights

Route · ONT → IAH · 2020–2025 BTS data

Ontario to Houston

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), ONT to IAH (Ontario to Houston) ranks #4170 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

81.9%
On-time
+2.9 pts
vs US avg
77 min
Delay when late
1,472
Flights
#4170 of 4927
Corpus placement

Cancelled

1.1%

Best Month

Apr 2025 85%

Worst Month

Mar 2025 76%

Distance

1,334 mi

Carriers

8

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 44 10 0 0 F9,UA
Nov 2025 47 4 0 0 UA,F9
Oct 2025 48 5 0 0 UA,F9
Sep 2025 43 7 0 0 UA,F9
Aug 2025 40 11 0 0 F9,UA
Jul 2025 38 7 0 0 UA,F9
Jun 2025 39 9 1 1 UA,F9
May 2025 44 4 1 0 UA,F9
Apr 2025 54 8 0 0 F9,UA
Mar 2025 59 14 1 0 UA,F9
Feb 2025 39 6 0 0 UA,F9
Jan 2025 41 7 2 0 UA,F9
Dec 2024 42 10 1 0 F9,UA
Nov 2024 47 6 0 0 UA,F9
Oct 2024 48 10 0 0 UA,F9
Sep 2024 47 11 1 0 UA,F9
Aug 2024 43 4 1 0 F9,UA
Jul 2024 49 19 2 0 F9,UA
Jun 2024 47 16 0 0 F9,UA
Jul 2022 31 6 0 0 UA
Jun 2022 30 8 1 0 UA
May 2022 31 6 0 0 UA
Apr 2022 30 3 0 0 UA
Mar 2022 31 2 0 0 UA

ONT–IAH seasonal on-time pattern

Best: January (90.4%) · weakest: July (66.4%)

60%70%80%90%100% JanFebMarAprMayJunJulAugSepOctNovDec 79.6%

Strongest calendar month

January

90.4% on-time · ~35 flights/mo

Busiest calendar month

November

~41 flights/mo avg

Weakest calendar month

July

66.4% on-time · ~37 flights/mo

Cancellation Rate

1.1%

11 of 1,012 flights

Diversion Rate

0.1%

1 of 1,012 flights

Origin-hub reliability standing

Mid-pack among ONT departures

From ONT, this corridor sits with 9 other 75–85% on-time routes out of 21 tracked departures, not the hub's reliability leaders (10 at ≥85%) and not the softest ( 2 below 75%). Destination: Houston · fleet on-time rank #2410 of 4927.

What the Data Says About ONT to IAH

1,472 tracked flights put the ONT to IAH pairing (Ontario to Houston) at a 81.9% on-time rate, squarely in line with the wider network. Delays that do occur run 76.7 minutes on average. Across the 1,334-mile route and its 8 carriers, the trailing 24 months show 1.1% cancelled and 0.1% diverted (1,012 flights sampled).

Monthly performance varies moderately here: Apr 2025 was the strongest month at 85% on-time versus Mar 2025 at 76%, a 9-point difference.

On the multi-year calendar, ONT–IAH peaks in January at 90.4% on-time while November carries the heaviest traffic (~41 flights per month) ; the softest month is July at 66.4%, a 24.0-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does ONT to IAH rank among US routes by traffic?
According to PlainFlights' route traffic ranking, ONT to IAH ranks #4170 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from ONT to IAH?
Flights from Ontario to Houston have a 81.9% on-time rate based on 1,472 flights. The average delay is 76.7 minutes. The best recent month was Apr 2025 with 85% on-time.
What is the cancellation rate for ONT to IAH?
Over the last 24 months, 1.1% of flights on this route were cancelled (11 of 1,012 flights) and 0.1% were diverted.
How far is the flight from ONT to IAH?
The flight distance from Ontario (ONT) to Houston (IAH) is approximately 1,334 miles. This route is served by 8 carriers.
When is the best time to fly from ONT to IAH?
The best recent month for on-time performance was Apr 2025 (85% on-time). The worst was Mar 2025 (76% on-time). Consider booking during months with historically better performance.

Airports on this route

Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Using ONT–IAH data

ONT–IAH is mid-pack at 81.9% on-time; month and carrier mix move more than the corridor headline.

  • Compare ONT and IAH airport profiles: delay causes and top routes differ even on the same corridor. ONT airport
  • If your dates flex, January (90.4% on-time) beats July (66.4%) on this corridor. Seasonal chart
  • 4 other routes post a similar 81.9% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.