STS to ONT flight delays & on-time performance
Nonstop flights from Charles M. Schulz Sonoma County Airport to Ontario International Airport · 423 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at STS or ONT right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Santa Rosa (STS) to Ontario (ONT) arrived on time 89% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0% were cancelled, and 5% arrived an hour or more late.
- SkyWest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 10am did best (90% on time); around 4pm did worst (88%).
- Monday was the most reliable day to fly (100% on time) and Tuesday the least (73%).
- The largest source of delay minutes was late-arriving aircraft (84%).
Which airline is most on time from STS 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 |
|---|---|---|---|---|---|
| SkyWest AirlinesRegional airline operating flights for United Express, Delta Connection, American Eagle and Alaska. | 89% | 0.0% | 9 min | 4.6% | 108 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 10am90%21 flights
- 2pm89%35 flights
- 4pm88%52 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday100%0.0% cancelled
- Tuesday73%0.0% cancelled
- Wednesday94%0.0% cancelled
- Thursday100%0.0% cancelled
- Friday88%0.0% cancelled
- Saturday80%0.0% cancelled
- Sunday87%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 aircraft84%
- Air traffic control & airport congestion11%
- Airline (crew, maintenance, cleaning, fueling)5%
- Extreme weather0%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
No cancellation causes recorded in this period.
STS to ONT: common questions
- How often are STS to ONT flights on time?
- 89% 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 Santa Rosa to Ontario cancelled?
- 0.0% of scheduled flights were cancelled (0 of 108).
- 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 74 min behind schedule on average, and 4.6% of flights were an hour or more late.
- How long is taxi time at STS?
- Flights on this route spent 15 min taxiing from the gate to takeoff on average.
Related routes
Return trip: ONT to STS — 90% on time
More flights from Santa Rosa
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: STS → ONT, nonstop flights by US airlines that report to the DOT. How we calculate this.