ONT to STS flight delays & on-time performance
Nonstop flights from Ontario International Airport to Charles M. Schulz Sonoma County Airport · 423 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at ONT or STS 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 Santa Rosa (STS) arrived on time 90% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0% were cancelled, and 3% arrived an hour or more late.
- SkyWest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 4pm did best (94% on time); around 12pm did worst (86%).
- Monday was the most reliable day to fly (100% on time) and Saturday the least (80%).
- The largest source of delay minutes was late-arriving aircraft (55%).
Which airline is most on time from ONT to STS?
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. | 90% | 0.0% | 8 min | 2.8% | 108 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 12pm86%21 flights
- 4pm94%35 flights
- 6pm88%52 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday100%0.0% cancelled
- Tuesday87%0.0% cancelled
- Wednesday100%0.0% cancelled
- Thursday88%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 aircraft55%
- Airline (crew, maintenance, cleaning, fueling)27%
- Air traffic control & airport congestion11%
- Extreme weather6%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
No cancellation causes recorded in this period.
ONT to STS: common questions
- How often are ONT to STS flights on time?
- 90% 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 Santa Rosa cancelled?
- 0.0% of scheduled flights were cancelled (0 of 108).
- How long are typical delays?
- Across all flights the average arrival delay was 8 min (early arrivals count as zero). Flights that were late arrived 67 min behind schedule on average, and 2.8% 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: STS to ONT — 89% 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 → STS, nonstop flights by US airlines that report to the DOT. How we calculate this.