ONT (Ontario) to IAH (Houston) flights arrive on time 81% of the time. The most reliable airline on this route is United Airlines at 89%. The average delay is 72 minutes. Delays on this route are most often caused by air traffic and busy airspace.
Source: Bureau of Transportation Statistics. Updated March 2026.ONT → IAH
ONT (Ontario) to IAH (Houston)
ONT → IAH on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is on time most of the time. About 81% of flights arrive on schedule.
Delays on this route are most often caused by air traffic and busy airspace.
Accurate?
United Airlines is significantly more reliable on this route at 89% on time vs Frontier Airlines at 65%.
Airline Comparison
United Airlines leads at 89% on time; Frontier Airlines trails at 65%.
Accurate?
Good to know
Departing from ONT
82% on timeTSA is currently ~16 min. Best time: 4 AM (about 5 min).
Arriving at IAH
80% on timeWhen flights into IAH are late, the average delay is 75 minutes. Build buffer if you have ground plans.
If connecting at IAH: TSA is ~11 min right now. Allow at least 60 minutes for a domestic connection.
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Data last updated March 2026. Source: Bureau of Transportation Statistics.