Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: Southwest’s ONT → SJC flights land within a few points of 86% on time whatever the hour.

Nonstops


Southwest	ONT	SJC	1h 15m	86%	0.1%	1,319	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach San Jose on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


Southwest Details →	ONT 05:15 → PHX 06:30WN 864	3h 10m Phoenix	PHX 09:40 → SJC 11:35WN 3336	6h 20m	98%	94%
Alaska Details →	ONT 10:54 → PDX 13:09AS 1699	1h 21m Portland	PDX 14:30 → SJC 16:25AS 3210 · flown by SkyWest	5h 31m	98%	92%
Alaska Details →	ONT 07:00 → PDX 09:15AS 345	2h 30m Portland	PDX 11:45 → SJC 13:35AS 1632	6h 35m	100%	88%
Delta Details →	ONT 06:00 → SLC 08:50DL 2708	2h 50m Salt Lake City	SLC 11:40 → SJC 12:38DL 1254	6h 38m	98%	88%
Southwest Details →	ONT 08:35 → LAS 09:40WN 2333	2h 30m Las Vegas	LAS 12:10 → SJC 13:45WN 1242	5h 10m	100%	88%
Delta Details →	ONT 09:40 → SLC 12:28DL 1302	2h 43m Salt Lake City	SLC 15:11 → SJC 16:07DL 1260	6h 27m	100%	88%
Delta Details →	ONT 06:20 → SEA 09:17DL 3816 · flown by SkyWest	2h 28m Seattle	SEA 11:45 → SJC 14:11DL 3789 · flown by SkyWest	7h 51m	99%	83%
Delta Details →	ONT 17:21 → SLC 20:17DL 4443 · flown by SkyWest	2h 28m Salt Lake City	SLC 22:45 → SJC 23:39DL 1272	6h 18m	96%	79%
Tight connection: often missed
Southwest Details →	ONT 16:40 → LAS 17:45WN 2213	1h 30m Las Vegas	LAS 19:15 → SJC 20:45WN 3865	4h 05m	74%	33%
Southwest Details →	ONT 14:30 → DEN 17:40WN 3147	1h 15m Denver	DEN 18:55 → SJC 20:25WN 1727	5h 57m	56%	16%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

PHX · 1h 15m · leaves 05:15 2%

DEN · 1h 05m · leaves 08:05 4%

DFW · 1h 19m · leaves 05:34 7%

Afternoon and evening

SEA · 1h 00m · leaves 14:05 23%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.


American AA 1194 ONT 06:11 → PHX Southwest WN 3336 PHX 09:40 → SJC Connection details →	2h 10m	5h 24m	94%	90%
Alaska AS 654 ONT 12:04 → SEA Delta DL 4100 SEA 17:50 → SJC Connection details →	3h 06m	8h 08m	99%	83%
Alaska AS 607 ONT 06:02 → SEA Delta DL 3789 SEA 11:45 → SJC Connection details →	3h 01m	8h 09m	99%	82%

Rank all connections, any airlines →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON