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

No clear winner: airlines and hours on this route all land within a few points of 78% on time.

Nonstops


Frontier	ONT	LAS	1h 12m	78%	1.5%	728	Flying now
Southwest	ONT	LAS	1h 05m	78%	0.7%	1,748	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


Southwest Details →	ONT 06:30 → SJC 07:50WN 383	1h 20m San Jose	SJC 09:10 → LAS 10:40WN 2369	4h 10m	100%	95%
Southwest Details →	ONT 05:15 → PHX 06:30WN 864	1h 00m Phoenix	PHX 07:30 → LAS 08:40WN 2336	3h 25m	98%	93%
Southwest Details →	ONT 06:00 → SMF 07:25WN 3165	3h 25m Sacramento	SMF 10:50 → LAS 12:20WN 1285	6h 20m	98%	90%
American Details →	ONT 06:11 → PHX 07:30AA 1194	2h 54m Phoenix	PHX 10:24 → LAS 11:37AA 2037	5h 26m	97%	86%
Southwest Details →	ONT 06:12 → OAK 07:38WN 3042	1h 22m Oakland	OAK 09:00 → LAS 10:30WN 2374	4h 18m	100%	86%
Alaska Details →	ONT 07:00 → PDX 09:15AS 345	1h 30m Portland	PDX 10:45 → LAS 13:11AS 757	6h 11m	100%	84%
Southwest Details →	ONT 05:50 → DEN 09:05WN 3144	1h 55m Denver	DEN 11:00 → LAS 11:55WN 1561	6h 05m	100%	83%
Southwest Details →	ONT 10:50 → SJC 12:00WN 3162	1h 40m San Jose	SJC 13:40 → LAS 15:10WN 714	4h 20m	97%	82%
Tight connection: often missed
Southwest Details →	ONT 18:30 → SMF 19:55WN 3170	50m Sacramento	SMF 20:45 → LAS 22:15WN 3788	3h 45m	67%	43%
Southwest Details →	ONT 16:00 → OAK 17:15WN 3155	55m Oakland	OAK 18:10 → LAS 19:45WN 4693	3h 45m	74%	40%
United Details →	ONT 18:39 → SFO 20:07UA 5624 · flown by SkyWest	1h 08m San Francisco	SFO 21:15 → LAS 23:10UA 406	4h 31m	21%	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 00m · leaves 05:15 2%

SFO · 1h 17m · leaves 06:00 4%

DEN · 1h 01m · leaves 06:00 10%

Afternoon and evening

SMF · 50m · leaves 18:30 33%

PHX · 47m · leaves 20:42 70%

SFO · 1h 08m · leaves 18:39 79%

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 864 ONT 05:15 → PHX American AA 2037 PHX 10:24 → LAS Connection details →	3h 54m	6h 22m	98%	88%
Southwest WN 2298 ONT 13:20 → SMF Frontier F9 2070 SMF 18:28 → LAS Connection details →	3h 48m	6h 37m	100%	83%
Southwest WN 3144 ONT 05:50 → DEN United UA 526 DEN 11:22 → LAS Connection details →	2h 17m	6h 34m	100%	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