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 3 in 4 on time.

Nonstops (seasonal or thin)


Southwest	ONT	AUS	2h 45m	76%	0.3%	336	Flying now
Delta	ONT	AUS	–	0%few flights	0.0%	1	Not flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Austin on time. Total trip = scheduled departure to arrival, layover included (Austin is 2 h ahead of Ontario). Layovers up to 4 hours. Pick a connection for the details.


Alaska Details →	ONT 07:00 → PDX 09:15AS 345	1h 15m Portland	PDX 10:30 → AUS 16:38AS 540	7h 38m	100%	86%
Southwest Details →	ONT 05:30 → LAS 06:35WN 3150	1h 05m Las Vegas	LAS 07:40 → AUS 12:25WN 1864	4h 55m	97%	85%
Southwest + Americantwo ticketsDetails →	ONT 05:15 → PHX 06:30WN 864	2h 14m Phoenix	PHX 08:44 → AUS 13:12AA 1394	5h 57m	98%	84%
Southwest Details →	ONT 05:50 → DEN 09:05WN 3144	55m Denver	DEN 10:00 → AUS 13:20WN 2263	5h 30m	95%	83%
Delta Details →	ONT 13:00 → SLC 15:47DL 3172	1h 58m Salt Lake City	SLC 17:45 → AUS 21:32DL 2728	6h 32m	98%	80%
United Details →	ONT 05:00 → DEN 08:20UA 2446	1h 45m Denver	DEN 10:05 → AUS 13:20UA 1026	6h 20m	98%	80%
Southwest + Unitedtwo ticketsDetails →	ONT 08:05 → DEN 11:15WN 3145	2h 29m Denver	DEN 13:44 → AUS 16:58UA 2270	6h 53m	96%	80%
United Details →	ONT 13:50 → SFO 15:15UA 1375	2h 06m San Francisco	SFO 17:21 → AUS 23:04UA 2332	7h 14m	91%	80%
Tight connection: often missed
American Details →	ONT 14:15 → DFW 19:30AA 2239	1h 03m Dallas-Fort Worth	DFW 20:33 → AUS 21:37AA 2707	5h 22m	59%	29%

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 05m · leaves 05:30 3%

DEN · 55m · leaves 05:50 5%

PHX · 1h 14m · leaves 06:11 8%

Afternoon and evening

DFW · 1h 03m · leaves 14:15 41%

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.

The table above includes two-ticket connections (marked “two tickets”), held to the 90-minute minimum. One ticket only →

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