SMF to ONT flight delays & on-time performance
Nonstop flights from Sacramento International Airport to Ontario International Airport · 390 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at SMF or ONT right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Sacramento (SMF) to Ontario (ONT) arrived on time 84% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.4% were cancelled, and 5% arrived an hour or more late.
- Southwest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 5am did best (97% on time); around 7pm did worst (72%).
- Wednesday was the most reliable day to fly (87% on time) and Thursday the least (81%).
- The largest source of delay minutes was late-arriving aircraft (68%).
Which airline is most on time from SMF 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 |
|---|---|---|---|---|---|
| Southwest Airlines | 84% | 0.4% | 9 min | 4.5% | 2,115 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 5am97%68 flights
- 6am96%236 flights
- 7am97%37 flights
- 8am90%165 flights
- 9am94%171 flights
- 10am87%91 flights
- 11am86%152 flights
- 12pm83%142 flights
- 1pm81%120 flights
- 2pm84%86 flights
- 3pm79%110 flights
- 4pm73%133 flights
- 5pm76%90 flights
- 6pm84%223 flights
- 7pm72%77 flights
- 8pm73%194 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday85%0.6% cancelled
- Tuesday86%0.0% cancelled
- Wednesday87%0.3% cancelled
- Thursday81%0.6% cancelled
- Friday83%0.6% cancelled
- Saturday86%0.6% cancelled
- Sunday84%0.0% 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 aircraft68%
- Airline (crew, maintenance, cleaning, fueling)28%
- Air traffic control & airport congestion4%
- Extreme weather0%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)75%
- Extreme weather25%
- Air traffic control & airport congestion0%
- Security0%
SMF to ONT: common questions
- How often are SMF to ONT flights on time?
- 84% 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 Sacramento to Ontario cancelled?
- 0.4% of scheduled flights were cancelled (8 of 2,115).
- How long are typical delays?
- Across all flights the average arrival delay was 9 min (early arrivals count as zero). Flights that were late arrived 51 min behind schedule on average, and 4.5% of flights were an hour or more late.
- How long is taxi time at SMF?
- Flights on this route spent 11 min taxiing from the gate to takeoff on average.
Related routes
Return trip: ONT to SMF — 86% on time
More flights from Sacramento
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: SMF → ONT, nonstop flights by US airlines that report to the DOT. How we calculate this.