IAH (Houston) to ONT (Ontario) flights arrive on time 63% of the time. The most reliable airline on this route is United Airlines at 67%. The average delay is 67 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated March 2026.IAH → ONT
IAH (Houston) to ONT (Ontario)
IAH → ONT on-time performance by month
24
25
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
Better
This route is frequently delayed. About 63% of flights arrive on schedule.
Delays on this route are most often caused by the incoming plane arriving late.
Accurate?
United Airlines edges out Frontier Airlines on this route — 67% vs 58% on time.
Airline Comparison
United Airlines leads at 67% on time; Frontier Airlines trails at 58%.
Accurate?
Good to know
Departing from IAH
80% on timeExpect ~18 min sitting on the taxiway after your gate pushes back. IAH has long runway queues.
TSA is currently ~11 min. Best time: 4 AM (about 5 min).
Arriving at ONT
82% on timeWhen flights into ONT are late, the average delay is 63 minutes. Build buffer if you have ground plans.
If connecting at ONT: TSA is ~16 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what United Airlines owes you — refund rights, action plan, complaint email. Free.
Free flight briefing
Know before you go
Flying IAH → ONT? We'll brief you before takeoff.
Delay riskDOT stats + live data
TSA waitCurrent checkpoint lines
WeatherBoth airports
Gate & terminalLive updates
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated March 2026. Source: Bureau of Transportation Statistics.