PlainFlights

Route · IAH → ONT · 2020–2025 BTS data

Houston to Ontario

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAH to ONT (Houston to Ontario) ranks #4167 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

71.9%
On-time
-7.1 pts
vs US avg
69 min
Delay when late
1,475
Flights
#4167 of 4927
Corpus placement

Cancelled

1.4%

Best Month

Apr 2025 70%

Worst Month

Mar 2025 63%

Distance

1,334 mi

Carriers

8

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 44 12 0 1 F9,UA
Nov 2025 47 15 0 0 UA,F9
Oct 2025 48 15 0 0 UA,F9
Sep 2025 43 8 0 0 UA,F9
Aug 2025 40 15 1 0 F9,UA
Jul 2025 39 17 0 0 UA,F9
Jun 2025 39 25 1 0 UA,F9
May 2025 45 18 0 0 UA,F9
Apr 2025 54 16 1 0 F9,UA
Mar 2025 59 22 1 0 UA,F9
Feb 2025 39 7 1 0 UA,F9
Jan 2025 41 13 2 1 UA,F9
Dec 2024 42 16 1 0 F9,UA
Nov 2024 47 11 0 0 UA,F9
Oct 2024 48 18 0 0 UA,F9
Sep 2024 47 16 0 0 UA,F9
Aug 2024 43 18 0 0 F9,UA
Jul 2024 49 24 5 0 F9,UA
Jun 2024 47 23 0 0 F9,UA
Jul 2022 31 7 0 0 UA
Jun 2022 30 13 1 0 UA
May 2022 31 6 0 0 UA
Apr 2022 30 8 0 0 UA
Mar 2022 31 6 0 0 UA

IAH–ONT seasonal on-time pattern

Best: January (83.5%) · weakest: June (55.8%)

50%60%70%80%90% JanFebMarAprMayJunJulAugSepOctNovDec 73.6%

Strongest calendar month

January

83.5% on-time · ~34 flights/mo

Busiest calendar month

November

~41 flights/mo avg

Weakest calendar month

June

55.8% on-time · ~37 flights/mo

Cancellation Rate

1.4%

14 of 1,014 flights

Diversion Rate

0.2%

2 of 1,014 flights

Origin-hub reliability standing

Softer reliability from IAH

Among 102 routes leaving IAH, only 6 (including this one) clear below 75% on-time, while 17 stay ≥85% and 79 sit mid-band. Travelers comparing IAH options should weigh this 71.9% print against those peers · fleet on-time rank #4762 of 4927.

What the Data Says About IAH to ONT

On-time performance on the IAH to ONT pairing (Houston to Ontario) trails a chunk of the network: 71.9% of 1,475 tracked flights arrived on schedule, with a 68.9-minute average delay on the ones that ran late. The route spans about 1,334 miles across 8 carriers. Cancellations over the trailing 24 months hit 1.4% (14 of 1,014 flights), with 0.2% diverted.

Monthly performance varies moderately here: Apr 2025 was the strongest month at 70% on-time versus Mar 2025 at 63%, a 8-point difference.

On the multi-year calendar, IAH–ONT peaks in January at 83.5% on-time while November carries the heaviest traffic (~41 flights per month) ; the softest month is June at 55.8%, a 27.7-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAH to ONT rank among US routes by traffic?
According to PlainFlights' route traffic ranking, IAH to ONT ranks #4167 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 IAH to ONT?
Flights from Houston to Ontario have a 71.9% on-time rate based on 1,475 flights. The average delay is 68.9 minutes. The best recent month was Apr 2025 with 70% on-time.
What is the cancellation rate for IAH to ONT?
Over the last 24 months, 1.4% of flights on this route were cancelled (14 of 1,014 flights) and 0.2% were diverted.
How far is the flight from IAH to ONT?
The flight distance from Houston (IAH) to Ontario (ONT) is approximately 1,334 miles. This route is served by 8 carriers.
When is the best time to fly from IAH to ONT?
The best recent month for on-time performance was Apr 2025 (70% on-time). The worst was Mar 2025 (63% 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 IAH–ONT data

IAH–ONT sits 7.1 pts below the national 79% average; check the seasonal chart and airport profiles before treating the headline as typical.

  • Compare IAH and ONT airport profiles: delay causes and top routes differ even on the same corridor. IAH airport
  • If your dates flex, January (83.5% on-time) beats June (55.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 71.9% 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.