Ontario (ONT) to Las Vegas (LAS): On-Time Performance
Data through May 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 79% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 71%), which matters most in the rough months.
- On-time
- 79%
- arrived <15 min late
- Avg delay
- 17 min
- completed flights
- Cancelled
- 0.9%
- 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 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Southwest Airlinesmost reliable | 80% | 12 min | 0.5% | 3,578 |
| Frontier Airlines | 77% | 26 min | 1.7% | 1,675 |
Monthly on-time trend
Best time to fly from ONT to LAS
Aim for departures around 5 a.m. (97% on-time); avoid 5 p.m. departures (64%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 20 min |
| Tuesday | 85% | 15 min |
| Wednesday | 85% | 9 min |
| Thursday | 75% | 19 min |
| Friday | 70% | 22 min |
| Saturdaybest | 87% | 14 min |
| Sunday | 80% | 14 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft50%
- Airline operations24%
- National airspace system24%
- Weather2%
Frequently asked questions
- How often are flights from ONT to LAS delayed?
- 21% of ONT–LAS flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 17 minutes.
- Which airline is most reliable from ONT to LAS?
- Southwest Airlines has the best on-time record on this route at 80%, based on 3,578 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 5 p.m. have the worst (64%). 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 21% of the time.
- How often are ONT to LAS flights cancelled?
- 0.9% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, 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.
Explore related pages
More routes from ONT
Based on 5,253 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.