Is STL–ONT running on time right now?
Mostly on schedule. The departure side at STL is the weaker end, route health score 68/100. The airports section above carries the live status and delay window at both ends.
live
Direct flights from St Louis (STL) to Ontario (ONT) run nonstop between the two airports. The nonstop covers 2,483 km, an estimated 3 hours 41 minutes in the air.
STL
St Louis
heavy · +48
ONT
Ontario
smooth · +0
2,483 km · ~3h 41m est.
Under pressure · 0 airlines · nonstop
68 / 100
route health from live STL and ONT delay boards
Flight time~3h 41mestimated from route distance
Airports right now
live boardsWeather lens
Current conditions put the pressure at STL and ONT: 44% odds of a 15+ minute delay and around +9 min expected when it bites, measured from this route's own weather-matched delay history. See live delays → · Weather risk by airport →
next sweep in 120s
How the St Louis to Ontario route actually runs
Pro Flight Search records official board updates for nonstop STL to ONT flights through the day: schedules, estimates, gate pushes and actual departures. The verdict above comes from operated flights, so it reflects what this route does rather than what the timetable promises.
Planning around a delay? Live airport delays · Weather delay risk map · Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Cite this data
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Suggested citation
Pro Flight Search — St Louis (STL) to Ontario (ONT) route reliability, measured from operated flights on official airport boards.
Canonical URL
How we measure this →
https://proflightsearch.com/search-flights/STL-ONT
STL to ONT questions
How long is the flight from STL to ONT?
Great-circle distance is 2,483 km. With typical jet cruise speed plus taxi, climb and descent, expect roughly 205–243 min gate-to-gate on this route.
What does the route health score measure?
A blend of departure-side delay at STL and arrival-side delay at ONT, computed from rolling delay windows (refreshed every 40 minutes) with a daily-rollup fallback. Current MVFR, IFR, or LIFR endpoint weather caps the score when flight rules can limit throughput. Higher is healthier: 100 means operations are clean at both ends.
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