Best Time to Fly SJC to ONT: On-Time Stats by Hour & Airline
Norman Y. Mineta San Jose International → Ontario International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 82.5% of San Jose (SJC) to Ontario (ONT) flights arrived on time (1,317 scheduled flights). That is 4.9 points above the national average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Tuesday was the most reliable day (90% on time) and June the worst month (75%).
The cancellation rate was 0.1% (US average 1.8%).
SJC to ONT 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 | 82.5% | 45 min | 0.1% | 1,317 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SJC to ONT
On-time arrival % by scheduled departure hour (local time), 2,694 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 98.8% | 0.4% | 243 |
| 7am–8am | 97.6% | 0.3% | 297 |
| 8am–9am | 97.0% | 1.2% | 171 |
| 9am–10am | 92.2% | 0.0% | 90 |
| 10am–11am | 91.9% | 0.6% | 174 |
| 11am–12pm | 87.2% | 0.0% | 266 |
| 12pm–1pm | 94.6% | 0.0% | 92 |
| 1pm–2pm | 84.4% | 0.0% | 96 |
| 2pm–3pm | 87.6% | 0.0% | 129 |
| 3pm–4pm | 79.0% | 0.0% | 62 |
| 4pm–5pm | 78.9% | 0.0% | 185 |
| 5pm–6pm | 74.3% | 0.0% | 187 |
| 6pm–7pm | 77.2% | 0.0% | 145 |
| 7pm–8pm | 84.4% | 0.0% | 182 |
| 8pm–9pm | 69.4% | 0.0% | 288 |
| 9pm–10pm | 52.9% | 0.0% | 86 |
| 10pm–11pm | Limited data | 1 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SJC to ONT
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) | 91.4% | +4.2 pts | 0.0% | 58 |
| Christmas & New Year (Dec 20 - Jan 3) | 76.8% | -10.3 pts | 0.9% | 109 |
| Summer peak (Jun 15 - Aug 15) | 78.4% | -8.8 pts | 0.4% | 479 |
| All other days | 87.2% | — | 0.1% | 2,048 |
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).