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


United	SFO	ONT	1h 27m	81%	0.5%	1,114	Flying now
Frontier	SFO	ONT	1h 34m	58%	3.1%	196	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 →	SFO 05:50 → SLC 08:42DL 1331	2h 37m Salt Lake City	SLC 11:19 → ONT 12:10DL 3172	6h 20m	99%	89%
Southwest Details →	SFO 05:30 → PHX 07:30WN 4145	2h 35m Phoenix	PHX 10:05 → ONT 11:20WN 431	5h 50m	100%	88%
United Details →	SFO 05:00 → DEN 08:35UA 1479	2h 50m Denver	DEN 11:25 → ONT 12:47UA 430	7h 47m	99%	87%
Delta Details →	SFO 17:07 → SLC 20:02DL 1088	2h 57m Salt Lake City	SLC 22:59 → ONT 23:48DL 1614	6h 41m	97%	84%
Delta Details →	SFO 09:55 → SLC 12:44DL 920	3h 01m Salt Lake City	SLC 15:45 → ONT 16:41DL 4443 · flown by SkyWest	6h 46m	97%	84%
Southwest Details →	SFO 05:00 → LAS 06:35WN 4231	2h 30m Las Vegas	LAS 09:05 → ONT 10:10WN 4179	5h 10m	100%	82%
American Details →	SFO 12:18 → PHX 14:29AA 2548	2h 38m Phoenix	PHX 17:07 → ONT 18:21AA 864	6h 03m	97%	81%
American Details →	SFO 05:50 → PHX 08:01AA 6404 · flown by SkyWest	2h 44m Phoenix	PHX 10:45 → ONT 12:02AA 2244	6h 12m	99%	72%
Tight connection: often missed
Frontier Details →	SFO 11:20 → LAS 13:10F9 4158	49m Las Vegas	LAS 13:59 → ONT 15:09F9 1357	3h 49m	60%	49%
Alaska Details →	SFO 17:38 → SEA 19:47AS 758	46m Seattle	SEA 20:33 → ONT 23:11AS 489	5h 33m	55%	39%
Alaska Details →	SFO 10:18 → SEA 12:27AS 656	1h 23m Seattle	SEA 13:50 → ONT 16:30AS 571	6h 12m	71%	35%

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

SEA · 1h 12m · leaves 07:03 11%

Afternoon and evening

PDX · 59m · leaves 18:46 18%

DEN · 1h 09m · leaves 14:20 20%

SEA · 46m · leaves 17:38 45%

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 1424 SFO 05:10 → DEN United UA 430 DEN 11:25 → ONT Connection details →	2h 45m	7h 37m	100%	88%
United UA 1301 SFO 10:15 → PDX Alaska AS 2093 PDX 14:30 → ONT Connection details →	2h 22m	6h 37m	93%	85%
American AA 6404 SFO 05:50 → PHX Southwest WN 431 PHX 10:05 → ONT Connection details →	2h 04m	5h 30m	96%	85%

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