LAS to ONT flight delays & on-time performance
Nonstop flights from Harry Reid International Airport to Ontario International Airport · 197 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at LAS or ONT right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Las Vegas (LAS) to Ontario (ONT) arrived on time 76% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0.7% were cancelled, and 7% arrived an hour or more late.
- Frontier Airlines was the most punctual airline here (82% on time); Southwest Airlines was the least (73%).
- Departures scheduled around 8am did best (95% on time); around 10pm did worst (44%).
- Tuesday was the most reliable day to fly (84% on time) and Friday the least (70%).
- The largest source of delay minutes was late-arriving aircraft (58%).
Which airline is most on time from LAS to ONT?
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 | 82% | 1.0% | 15 min | 6.9% | 727 |
| Southwest Airlines | 73% | 0.6% | 14 min | 6.6% | 1,749 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am94%66 flights
- 7am90%220 flights
- 8am95%125 flights
- 9am87%187 flights
- 10am81%126 flights
- 11am79%142 flights
- 12pm83%170 flights
- 1pm76%100 flights
- 2pm73%207 flights
- 3pm70%91 flights
- 4pm64%122 flights
- 5pm72%94 flights
- 6pm72%137 flights
- 7pm74%268 flights
- 8pm69%134 flights
- 9pm68%123 flights
- 10pm44%163 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday71%0.3% cancelled
- Tuesday84%0.3% cancelled
- Wednesday80%0.3% cancelled
- Thursday76%0.5% cancelled
- Friday70%1.0% cancelled
- Saturday81%1.5% cancelled
- Sunday71%1.3% 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%
- Airline (crew, maintenance, cleaning, fueling)33%
- Air traffic control & airport congestion7%
- Extreme weather2%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Air traffic control & airport congestion56%
- Airline (crew, maintenance, cleaning, fueling)33%
- Extreme weather11%
- Security0%
LAS to ONT: common questions
- How often are LAS to ONT flights on time?
- 76% 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 Las Vegas to Ontario cancelled?
- 0.7% of scheduled flights were cancelled (18 of 2,476).
- How long are typical delays?
- Across all flights the average arrival delay was 14 min (early arrivals count as zero). Flights that were late arrived 54 min behind schedule on average, and 6.7% of flights were an hour or more late.
- How long is taxi time at LAS?
- Flights on this route spent 16 min taxiing from the gate to takeoff on average.
Related routes
Return trip: ONT to LAS — 77% on time
More flights from Las Vegas
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: LAS → ONT, nonstop flights by US airlines that report to the DOT. How we calculate this.