ONT to LAS flight delays & on-time performance
Nonstop flights from Ontario International Airport to Harry Reid International Airport · 197 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at ONT or LAS right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Ontario (ONT) to Las Vegas (LAS) arrived on time 77% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0.9% were cancelled, and 7% arrived an hour or more late.
- Frontier Airlines was the most punctual airline here (77% on time); Southwest Airlines was the least (77%).
- Departures scheduled around 5am did best (98% on time); around 5pm did worst (61%).
- Saturday was the most reliable day to fly (86% on time) and Friday the least (67%).
- The largest source of delay minutes was late-arriving aircraft (58%).
Which airline is most on time from ONT to LAS?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Frontier Airlines | 77% | 1.5% | 21 min | 10.0% | 728 |
| Southwest Airlines | 77% | 0.7% | 12 min | 5.9% | 1,748 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 5am98%267 flights
- 6am94%180 flights
- 7am95%43 flights
- 8am92%205 flights
- 9am89%57 flights
- 10am82%132 flights
- 11am74%125 flights
- 12pm66%99 flights
- 1pm65%149 flights
- 2pm69%125 flights
- 3pm74%268 flights
- 4pm66%122 flights
- 5pm61%112 flights
- 6pm68%90 flights
- 7pm62%83 flights
- 8pm71%127 flights
- 9pm67%225 flights
- 10pm72%67 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday75%1.3% cancelled
- Tuesday82%0.3% cancelled
- Wednesday84%0.6% cancelled
- Thursday72%1.1% cancelled
- Friday67%0.8% cancelled
- Saturday86%0.7% cancelled
- Sunday77%1.5% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft58%
- Air traffic control & airport congestion25%
- Airline (crew, maintenance, cleaning, fueling)16%
- Extreme weather1%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)48%
- Air traffic control & airport congestion35%
- Extreme weather17%
- Security0%
ONT to LAS: common questions
- How often are ONT to LAS flights on time?
- 77% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Ontario to Las Vegas cancelled?
- 0.9% of scheduled flights were cancelled (23 of 2,476).
- How long are typical delays?
- Across all flights the average arrival delay was 15 min (early arrivals count as zero). Flights that were late arrived 61 min behind schedule on average, and 7.1% of flights were an hour or more late.
- How long is taxi time at ONT?
- Flights on this route spent 15 min taxiing from the gate to takeoff on average.
Related routes
Return trip: LAS to ONT — 76% on time
More flights from Ontario
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: ONT → LAS, nonstop flights by US airlines that report to the DOT. How we calculate this.