Ontario (ONT) to Las Vegas (LAS): On-Time Performance
Data through July 2026
Ontario (ONT) to Las Vegas (LAS) effectively runs on two schedules. In February 2026, 89% of arrivals were on time; in May 2026 that fell to 64% — a 24-point seasonal swing. Across the full period the route averages 78% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 70%), which matters most in the rough months.
- On-time
- 78%
- arrived <15 min late
- Avg delay
- 16 min
- completed flights
- Cancelled
- 0.8%
- Flights/day
- 6.8
- last 12 months
- Duration
- 1h 8m
- scheduled
- Distance
- 197 mi
Best airline from ONT to LAS
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Southwest Airlinesmost reliable | 79% | 12 min | 0.5% | 3,723 |
| Frontier Airlines | 76% | 25 min | 1.5% | 1,710 |
Monthly on-time trend
Best time to fly from ONT to LAS
Aim for departures around 5 a.m. (97% on-time); avoid 7 p.m. departures (65%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 20 min |
| Tuesday | 85% | 14 min |
| Wednesday | 84% | 9 min |
| Thursday | 74% | 20 min |
| Friday | 70% | 22 min |
| Saturdaybest | 87% | 12 min |
| Sunday | 79% | 15 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft51%
- Airline operations23%
- National airspace system24%
- Weather2%
Frequently asked questions
- How often are flights from ONT to LAS delayed?
- 22% of ONT–LAS flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 16 minutes.
- Which airline is most reliable from ONT to LAS?
- Southwest Airlines has the best on-time record on this route at 79%, based on 3,723 flights. 2 airlines flew ONT–LAS frequently enough to compare in this period.
- What is the best time of day to fly from ONT to LAS?
- Departures around 5 a.m. have the best record (97% on-time), while departures around 7 p.m. have the worst (65%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ONT to LAS?
- The scheduled ONT–LAS flight time averages 1h 8m over 197 miles. Actual arrival times vary — flights on this route land 15+ minutes late 22% of the time.
- How often are ONT to LAS flights cancelled?
- 0.8% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from ONT to LAS?
- May 2026 was the roughest month in this dataset, with only 64% of arrivals on time. The best was February 2026 at 89%. If your dates are flexible, that 24-point gap is worth planning around.
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Based on 5,433 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.