Best Time to Fly ONT to LAS: On-Time Stats by Hour & Airline
Ontario International → Harry Reid International
Data through July 2026 · Last updated October 18, 2026
2,476 flights were scheduled from Ontario (ONT) to Las Vegas (LAS) in the last 12 months, and 77.0% of those that flew arrived on time, 0.6 points below the US average of 77.6%.
Among 2 airlines, Frontier Airlines led with 77.3% on time and Southwest Airlines was last with 77.0%.
Over 24 months, Saturday was the most reliable day (87% on time) and June the worst month (71%).
The cancellation rate was 0.9% (US average 1.8%).
ONT to LAS 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 |
|---|---|---|---|---|
| Frontier Airlines | 77.3% | 87 min | 1.5% | 728 |
| Southwest Airlines | 77.0% | 50 min | 0.7% | 1,748 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ONT to LAS
On-time arrival % by scheduled departure hour (local time), 5,186 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 97.1% | 0.5% | 416 |
| 6am–7am | 94.5% | 0.7% | 421 |
| 7am–8am | 93.9% | 0.0% | 98 |
| 8am–9am | 92.9% | 0.5% | 383 |
| 9am–10am | 91.1% | 0.6% | 181 |
| 10am–11am | 83.1% | 1.9% | 265 |
| 11am–12pm | 79.3% | 0.4% | 247 |
| 12pm–1pm | 79.2% | 0.3% | 284 |
| 1pm–2pm | 70.4% | 0.0% | 318 |
| 2pm–3pm | 65.0% | 1.7% | 294 |
| 3pm–4pm | 69.8% | 1.0% | 485 |
| 4pm–5pm | 66.2% | 0.0% | 266 |
| 5pm–6pm | 64.6% | 1.6% | 244 |
| 6pm–7pm | 77.8% | 1.8% | 229 |
| 7pm–8pm | 63.8% | 1.3% | 225 |
| 8pm–9pm | 72.3% | 0.0% | 311 |
| 9pm–10pm | 67.8% | 1.2% | 343 |
| 10pm–11pm | 74.4% | 1.2% | 166 |
| 11pm–12am | Limited data | 10 | |
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 LAS
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) | 83.2% | +4.2 pts | 0.0% | 89 |
| Christmas & New Year (Dec 20 - Jan 3) | 81.3% | +2.4 pts | 0.5% | 210 |
| Summer peak (Jun 15 - Aug 15) | 73.2% | -5.8 pts | 1.4% | 866 |
| All other days | 79.0% | — | 0.7% | 4,021 |
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).