ONT to SJC flight delays
Ontario, CA (ONT) San Jose, CA (SJC) · 333 miles
114 flights · March 2025 – August 2026 · US Bureau of Transportation Statistics
75.44%
Arrived on time
Within 15 minutes of schedule
0%
Cancelled
Share of scheduled flights
62 min
When late, late by
Average across delayed arrivals
16 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Only Southwest Airlines flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.
Flights from Ontario to San Jose run late more often than the average route, though not severely.
Which airline should you fly on this route?
Over March 2025 – August 2026, Southwest Airlines arrived on time most often on ONT to SJC.
Every airline on ONT to SJC
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 114 | 75.44% | 0% | 62 min | C |
The return leg
SJC to ONT San Jose back to Ontario 71.68% on time COther routes from Ontario
Common questions
Are flights from Ontario to San Jose usually delayed?
75.44% of flights on the ONT to SJC route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airlines fly from Ontario to San Jose?
Only Southwest Airlines appears in the published record on this route, with 114 flights and 75.44% arriving on time.
How often are ONT to SJC flights cancelled?
0% of scheduled flights did not operate — about 1 in every thousand. That is in the normal range.
When ONT to SJC flights are late, how late are they?
About 62 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on ONT to SJC during March 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →