ONT (Ontario) to ATL (Atlanta) flights arrive on time 91% of the time. The most reliable airline on this route is Delta Air Lines at 91%. The average delay is 74 minutes. Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Source: Bureau of Transportation Statistics. Updated August 2026.ONT → ATL
ONT (Ontario) to ATL (Atlanta)
ONT → ATL on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is usually on time. About 91% of flights arrive on schedule.
Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Accurate?
Accurate?
Good to know
Departing from ONT
82% on timeTSA is currently ~27 min. Best time: 4 AM (about 5 min).
Arriving at ATL
80% on timeWhen flights into ATL are late, the average delay is 72 minutes. Build buffer if you have ground plans.
If connecting at ATL: TSA is ~12 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what Delta Air Lines owes you — refund rights, action plan, complaint email. Free.
Flying out of ONT? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated August 2026. Source: Bureau of Transportation Statistics.