Route profile
HOU→ONT
Flight reliability, delays and best times to fly from Houston to Ontario, 1,345 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
September 2023 – July 2026
Better than 77% of comparable major US routes (4,598 compared)
Calculated from 1,018 flights. How this is calculated · What counts as on time
HOU → ONT arrives on time 79.8% of the time; the return trip, ONT → HOU, arrives on time 78.9% of the time.
HOU → ONT spends 18.1 minutes on the ground on a 1,345-mile trip: 13.4 minutes from pushback to wheels-up at HOU and 4.7 minutes from touchdown to gate at ONT.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
What stands out
Reliability on this route has fallen unusually sharply over the past year, a bigger swing than 91% of 5,368 comparable routes.
78.1% on time over the most recent 12 months (2025-08 to 2026-07), against 87.5% in the 12 months before (2024-08 to 2025-07), a change of 9.4 points.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where HOU to ONT differs most from similar routes by hour, weekday, month and airline, September 2023 – July 2026.
HOU to ONT struggles most at 1 PM: 68.4% of its flights scheduled then arrive on time, 7.8 points behind the 76.2% on routes of similar length at the same hour. Against all other routes the gap is 8.7 points.
Southwest Airlines does better on HOU to ONT than on its routes of similar length: 79.8% on time here, 75.7% there, 4.1 points apart.
HOU to ONT against comparable routes
September 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 1 PM departures | 68.4% | routes of similar length | 76.2% | −7.8 pts | 212 here, 95,075 there |
| Airline: Southwest Airlines | 79.8% | routes of similar length | 75.7% | +4.1 pts | 1,012 here, 403,788 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,345 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
September 2023 – July 2026
31 min late
against a median of 3 min early
Percentiles over 1,018 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ONT after arriving from HOU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 39% | Likely to miss |
| 45 min | 19% | High risk |
| 60 min | 10% | Some risk |
| 90 min | 5.5% | Some risk |
| 120 min | 2.9% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.39% of the time and diverts 0.20% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,012 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 31 minutes late (90th-percentile gate arrival delay), over 1,018 operations.
Any other layover length: connection checker.
Best time to fly
HOU → ONT flights departing 5–9 AM arrived on time 88.6% of the time, against 71.5% for 12–3 PM departures, a gap of 17.1 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 88.9% on time from 216 flights
- 9 AM to 12 PM: too few flights to score
- 1 PM: 68.4% on time from 212 flights
- 2 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why HOU → ONT runs late
September 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for HOU → ONT. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on HOU → ONT, at 48.7%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 88.6% of the time and 12–3 PM departures 71.5%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Southwest Airlines | 1,018 | 79.8% | 0.39% | -3 min | 5.5% |
Other ways to fly Houston to Los Angeles
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| IAH→LAX Houston to Los Angeles | 16,491 | 82.8% | 1.01% | -8 min | 74 |
| HOU→ONT this route Houston to Ontario | 1,018 | 79.8% | 0.39% | -3 min | 76 |
Flying to ONT from the Houston area? Compare HOU, IAH for ONT, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 12.6 percentage points.
Reliability over time
September 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 78.1% against 87.5% in the 12 months before — declining by 9.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,018 HOU → ONT flight records from the US DOT Bureau of Transportation Statistics, covering September 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed