Best Time to Fly ONT to SJC: On-Time Stats by Hour & Airline
Ontario International → Norman Y. Mineta San Jose International
Data through July 2026 · Last updated October 18, 2026
1,319 flights were scheduled from Ontario (ONT) to San Jose (SJC) in the last 12 months, and 85.5% of those that flew arrived on time, 7.9 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
January has been the best month (93% on time) and Sunday the weakest day of the week (80%).
0.1% of flights were cancelled, versus 1.8% nationally.
ONT to SJC on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Southwest Airlines | 85.5% | 56 min | 0.1% | 1,319 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ONT to SJC
On-time arrival % by scheduled departure hour (local time), 2,703 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 98.2% | 0.0% | 56 |
| 6am–7am | 98.0% | 0.2% | 461 |
| 7am–8am | 97.0% | 0.0% | 33 |
| 8am–9am | 100.0% | 0.8% | 134 |
| 9am–10am | 93.4% | 0.9% | 107 |
| 10am–11am | 93.6% | 0.0% | 220 |
| 11am–12pm | 93.5% | 0.0% | 123 |
| 12pm–1pm | 89.6% | 0.0% | 163 |
| 1pm–2pm | 90.8% | 0.0% | 119 |
| 2pm–3pm | 88.7% | 0.0% | 97 |
| 3pm–4pm | 83.3% | 0.0% | 120 |
| 4pm–5pm | 78.3% | 0.0% | 244 |
| 5pm–6pm | 83.0% | 0.0% | 218 |
| 6pm–7pm | 84.3% | 0.0% | 121 |
| 7pm–8pm | 71.8% | 0.0% | 245 |
| 8pm–9pm | 70.8% | 0.0% | 212 |
| 9pm–10pm | 46.7% | 0.0% | 30 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ONT to SJC
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 90.0% | +1.6 pts | 0.0% | 60 |
| Christmas & New Year (Dec 20 - Jan 3) | 80.2% | -8.2 pts | 0.9% | 107 |
| Summer peak (Jun 15 - Aug 15) | 81.4% | -7.0 pts | 0.0% | 479 |
| All other days | 88.4% | — | 0.1% | 2,057 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).