ONT to IAH flight delays
Ontario, CA (ONT) Houston, TX (IAH) · 1,334 miles
60 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics
77.19%
Arrived on time
Within 15 minutes of schedule
5%
Cancelled
Share of scheduled flights
56 min
When late, late by
Average across delayed arrivals
14 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Cancellation, not delay, is the risk worth pricing here: 5% of scheduled flights never operated. A late flight still gets you there. A cancelled one leaves you rebooking, and on a route with few daily departures that can mean losing a day.
The two directions do not behave alike. IAH to ONT arrives on time 7.2 points less often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
The Ontario to Houston route sits close to the middle of the record — neither notably punctual nor notably late.
Every airline on ONT to IAH
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Frontier Airlines | 30 | 64.29% | 6.67% | 51 min | — |
| United Airlines | 30 | 89.66% | 3.33% | 73 min | — |
The return leg
IAH to ONT Houston back to Ontario 70% on time —Other routes from Ontario
Common questions
Are flights from Ontario to Houston usually delayed?
77.19% of flights on the ONT to IAH route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
How often are ONT to IAH flights cancelled?
5% of scheduled flights did not operate — about 50 in every thousand. That is high enough that cancellation, not delay, is the risk worth planning around.
When ONT to IAH flights are late, how late are they?
About 56 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on ONT to IAH during March 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →