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 OAK → ONT flights land within a few points of 83% on time whatever the hour.

Nonstops


Southwest	OAK	ONT	1h 20m	83%	0.4%	1,471	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


Delta Details →	OAK 06:00 → SLC 08:55DL 4061 · flown by SkyWest	2h 24m Salt Lake City	SLC 11:19 → ONT 12:10DL 3172	6h 10m	98%	89%
Delta Details →	OAK 17:05 → SLC 20:00DL 3903 · flown by SkyWest	2h 59m Salt Lake City	SLC 22:59 → ONT 23:48DL 1614	6h 43m	99%	88%
Southwest Details →	OAK 05:10 → PHX 07:05WN 3066	3h 00m Phoenix	PHX 10:05 → ONT 11:20WN 431	6h 10m	98%	87%
Alaska Details →	OAK 12:01 → PDX 13:44AS 3045 · flown by SkyWest	46m Portland	PDX 14:30 → ONT 16:52AS 2093 · flown by Horizon	4h 51m	93%	85%
Southwest Details →	OAK 07:35 → LAS 09:05WN 4348	2h 25m Las Vegas	LAS 11:30 → ONT 12:32WN 2298	4h 57m	100%	82%
Southwest Details →	OAK 05:00 → LAS 06:30WN 2325	2h 35m Las Vegas	LAS 09:05 → ONT 10:10WN 4179	5h 10m	98%	80%
Alaska Details →	OAK 06:22 → SEA 08:26AS 491	1h 59m Seattle	SEA 10:25 → ONT 13:09AS 565	6h 47m	100%	74%
Southwest Details →	OAK 10:15 → PHX 12:10WN 4766	1h 45m Phoenix	PHX 13:55 → ONT 15:05WN 670	4h 50m	98%	69%
Tight connection: often missed
Southwest Details →	OAK 19:50 → PHX 21:50WN 3070	1h 05m Phoenix	PHX 22:55 → ONT 00:08 +1WN 223	4h 17m	47%	36%
Alaska Details →	OAK 14:55 → SEA 17:00AS 1464	51m Seattle	SEA 17:51 → ONT 20:32AS 592	5h 37m	45%	33%
Southwest Details →	OAK 16:45 → LAS 18:20WN 4539	50m Las Vegas	LAS 19:10 → ONT 20:10WN 208	3h 25m	19%	10%

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

LAS · 1h 00m · leaves 09:00 14%

Afternoon and evening

PHX · 1h 05m · leaves 19:50 53%

SEA · 51m · leaves 14:55 55%

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.


Southwest WN 4198 OAK 09:30 → SLC Delta DL 4443 SLC 15:45 → ONT Connection details →	3h 30m	7h 11m	100%	87%
Southwest WN 3041 OAK 05:45 → DEN United UA 430 DEN 11:25 → ONT Connection details →	2h 10m	7h 02m	95%	84%
Alaska AS 705 OAK 10:22 → SEA Delta DL 4031 SEA 14:35 → ONT Connection details →	2h 09m	6h 57m	96%	83%

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