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 9 in 10 on time.

Nonstops


Delta	SLC	ONT	1h 51m	90%	0.9%	1,209	Flying now
Frontier	SLC	ONT	1h 53m	93%few flights	3.3%	30	Not 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 (Ontario is 1 h behind Salt Lake City). Layovers up to 4 hours. Pick a connection for the details.


Southwest Details →	SLC 05:45 → SMF 06:25WN 4981	2h 45m Sacramento	SMF 09:10 → ONT 10:30WN 3805	5h 45m	98%	90%
Alaska Details →	SLC 11:22 → PDX 12:23AS 2333 · flown by Horizon	2h 07m Portland	PDX 14:30 → ONT 16:52AS 2093 · flown by Horizon	6h 30m	95%	88%
Southwest Details →	SLC 06:15 → PHX 06:55WN 3751	3h 10m Phoenix	PHX 10:05 → ONT 11:20WN 431	6h 05m	98%	87%
United Details →	SLC 07:00 → DEN 08:42UA 1232	2h 43m Denver	DEN 11:25 → ONT 12:47UA 430	6h 47m	99%	87%
Delta Details →	SLC 11:35 → SEA 12:52DL 2995	1h 43m Seattle	SEA 14:35 → ONT 17:19DL 4031 · flown by SkyWest	6h 44m	97%	85%
Southwest Details →	SLC 06:25 → LAS 06:50WN 4205	2h 15m Las Vegas	LAS 09:05 → ONT 10:10WN 4179	4h 45m	100%	82%
Alaska Details →	SLC 06:23 → SEA 07:35AS 1444	58m Seattle	SEA 08:33 → ONT 11:14AS 1364	5h 51m	94%	81%
United Details →	SLC 16:21 → SFO 17:23UA 1955	3h 37m San Francisco	SFO 21:00 → ONT 22:37UA 552	7h 16m	97%	81%
Tight connection: often missed
American Details →	SLC 18:50 → PHX 19:37AA 4928 · flown by SkyWest	53m Phoenix	PHX 20:30 → ONT 21:44AA 1238	3h 54m	51%	37%
American Details →	SLC 14:00 → DFW 17:50AA 2613	1h 00m Dallas-Fort Worth	DFW 18:50 → ONT 19:59AA 2236	6h 59m	55%	33%
American Details →	SLC 16:42 → DFW 20:30AA 2594	57m Dallas-Fort Worth	DFW 21:27 → ONT 22:32AA 711	6h 50m	38%	18%

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 · 55m · leaves 06:15 12%

DEN · 1h 01m · leaves 06:05 16%

Afternoon and evening

PDX · 47m · leaves 19:39 37%

DFW · 57m · leaves 16:42 62%

PHX · 50m · leaves 21:25 71%

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.


United UA 5683 SLC 05:15 → DEN Frontier F9 2907 DEN 08:44 → ONT Connection details →	1h 50m	5h 50m	96%	87%
Southwest WN 3738 SLC 07:45 → DEN United UA 430 DEN 11:25 → ONT Connection details →	2h 10m	6h 02m	98%	87%
Delta DL 1209 SLC 11:15 → PDX Alaska AS 2093 PDX 14:30 → ONT Connection details →	2h 20m	6h 37m	96%	87%

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