OAK → ONT: cancellations & delays
Over Jan 2023 - Apr 2026, 0.5% of Oakland San Francisco Bay Airport (OAK) to Ontario International Airport (ONT) flights were cancelled and 15.2% arrived at least 15 minutes late, across 5,230 flights, flown by WN. Cancellations peak in January.
Check today's live OAK departures →Airport pages: Oakland San Francisco Bay Airport (OAK) · Ontario International Airport (ONT)
Rates are historical averages from U.S. DOT (BTS) on-time records; a specific flight's live estimate can differ with weather and the day's disruptions.