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Route · SJC → ONT · 2020–2025 BTS data

San Jose to Ontario

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SJC to ONT (San Jose to Ontario) ranks #1560 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

85.6%
On-time
+6.6 pts
vs US avg
55 min
Delay when late
7,922
Flights
#1560 of 4927
Corpus placement

Cancelled

0.3%

Best Month

Nov 2024 94%

Worst Month

Oct 2025 72%

Distance

333 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 118 18 0 0 WN
Nov 2025 116 14 0 0 WN
Oct 2025 110 31 0 0 WN
Sep 2025 107 16 0 1 WN
Aug 2025 110 17 0 0 WN
Jul 2025 118 22 0 0 WN
Jun 2025 115 24 0 0 WN
May 2025 123 15 0 0 WN
Apr 2025 114 12 0 0 WN
Mar 2025 106 11 0 0 WN
Feb 2025 91 8 0 0 WN
Jan 2025 101 8 3 2 WN
Dec 2024 110 15 0 0 WN
Nov 2024 110 7 0 0 WN
Oct 2024 123 15 0 0 WN
Sep 2024 132 18 0 0 WN
Aug 2024 134 10 0 0 WN
Jul 2024 116 21 2 0 WN
Jun 2024 115 22 0 0 WN
May 2024 108 20 0 0 WN
Apr 2024 104 11 0 0 WN
Mar 2024 102 22 0 0 WN
Feb 2024 99 10 1 0 WN
Jan 2024 110 17 1 0 WN

SJC–ONT seasonal on-time pattern

Best: January (90.4%) · weakest: July (81.3%)

80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 84.3%

Strongest calendar month

January

90.4% on-time · ~109 flights/mo

Busiest calendar month

August

~120 flights/mo avg

Weakest calendar month

July

81.3% on-time · ~119 flights/mo

Cancellation Rate

0.3%

7 of 2,692 flights

Diversion Rate

0.1%

3 of 2,692 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

SJC - San Jose

Full on-time, delay-cause, and seasonal performance for San Jose, CA.

SJC on-time profile

ONT - Ontario

Full on-time, delay-cause, and seasonal performance for Ontario, CA.

ONT on-time profile

Compare the two airports

See SJC and ONT side by side on delays, cancellations, and reliability.

Compare SJC vs ONT

Origin-hub reliability standing

Among SJC's stronger departures

SJC → ONT posts a 85.6% on-time rate, landing in the ≥85% band with 21 of 31 BTS-tracked routes leaving San Jose. The same hub also shows 9 mid-band and 1 challenged departures · fleet-wide on-time rank #1043 of 4927 (highest on-time = #1).

What the Data Says About SJC to ONT

San Jose to Ontario (SJC to ONT) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 85.6% on-time rate across 7,922 flights, with delays that do happen averaging 55.4 minutes. The corridor runs roughly 333 miles and is served by 1 carrier. Over the most recent 24 months, 7 of 2,692 flights were cancelled (0.3%) and 3 diverted (0.1%).

The monthly split is wide on this route: Nov 2024 posted the strongest performance at 94% on-time, while Oct 2025 came in at just 72% - a 22-point swing worth factoring into travel timing.

On the multi-year calendar, SJC–ONT peaks in January at 90.4% on-time while August carries the heaviest traffic (~120 flights per month) ; the softest month is July at 81.3%, a 9.1-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SJC to ONT rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SJC to ONT ranks #1560 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from SJC to ONT? ▼
Flights from San Jose to Ontario have a 85.6% on-time rate based on 7,922 flights. The average delay is 55.4 minutes. The best recent month was Nov 2024 with 94% on-time.
What is the cancellation rate for SJC to ONT? ▼
Over the last 24 months, 0.3% of flights on this route were cancelled (7 of 2,692 flights) and 0.1% were diverted.
How far is the flight from SJC to ONT? ▼
The flight distance from San Jose (SJC) to Ontario (ONT) is approximately 333 miles. This route is served by 1 carrier.
When is the best time to fly from SJC to ONT? ▼
The best recent month for on-time performance was Nov 2024 (94% on-time). The worst was Oct 2025 (72% on-time). Consider booking during months with historically better performance.

Airports on this route

SJC Airport

San Jose
ONT Airport

Ontario
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using SJC–ONT data

SJC–ONT runs 6.6 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SJC and ONT airport profiles: delay causes and top routes differ even on the same corridor. SJC airport
  • If your dates flex, January (90.4% on-time) beats July (81.3%) on this corridor. Seasonal chart
  • 4 other routes post a similar 85.6% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.