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 86% on time.

Nonstops (seasonal or thin)


United	ONT	IAH	3h 19m	91%	0.5%	365	Flying now
Frontier	ONT	IAH	3h 25m	76%	2.0%	196	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


American Details →	ONT 22:10 → CLT 05:48AA 2237	1h 54m Charlotte	CLT 07:42 → IAH 09:25 +1AA 1930	9h 15m	97%	88%
United Details →	ONT 06:00 → SFO 07:25UA 2363	1h 30m San Francisco	SFO 08:55 → IAH 15:07UA 2498	7h 07m	96%	85%
Alaska Details →	ONT 12:04 → SEA 14:44AS 654	2h 49m Seattle	SEA 17:33 → IAH 23:59AS 1579	9h 55m	100%	84%
United Details →	ONT 18:39 → SFO 20:07UA 5624 · flown by SkyWest	3h 52m San Francisco	SFO 23:59 → IAH 06:04 +1UA 505	9h 25m	100%	81%
United Details →	ONT 13:50 → SFO 15:15UA 1375	3h 39m San Francisco	SFO 18:54 → IAH 00:59 +1UA 1702	9h 09m	97%	80%
Delta Details →	ONT 09:40 → SLC 12:28DL 1302	1h 17m Salt Lake City	SLC 13:45 → IAH 17:53DL 1299	6h 13m	100%	79%
Delta Details →	ONT 13:00 → SLC 15:47DL 3172	1h 58m Salt Lake City	SLC 17:45 → IAH 21:52DL 2514	6h 52m	98%	77%
United Details →	ONT 13:18 → DEN 16:38UA 1263	3h 50m Denver	DEN 20:28 → IAH 23:59UA 2419	8h 41m	97%	77%
Tight connection: often missed
Alaska Details →	ONT 14:05 → SEA 16:45AS 567	48m Seattle	SEA 17:33 → IAH 23:59AS 1579	7h 54m	61%	53%
American Details →	ONT 12:35 → DFW 17:50AA 2242	46m Dallas-Fort Worth	DFW 18:36 → IAH 19:54AA 1392	5h 19m	69%	32%
American Details →	ONT 14:15 → DFW 19:30AA 2239	1h 40m Dallas-Fort Worth	DFW 21:10 → IAH 22:24AA 2209	6h 09m	71%	32%

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

DFW · 1h 17m · leaves 05:34 7%

Afternoon and evening

ATL · 1h 10m · leaves 11:50 11%

DFW · 46m · leaves 12:35 31%

SEA · 48m · leaves 14:05 39%

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 3150 ONT 05:30 → LAS United UA 1711 LAS 10:25 → IAH Connection details →	3h 50m	8h 10m	100%	91%
Alaska AS 607 ONT 06:02 → SEA United UA 2293 SEA 11:55 → IAH Connection details →	3h 11m	10h 33m	99%	88%
Southwest WN 3166 ONT 09:45 → SMF United UA 1949 SMF 13:15 → IAH Connection details →	2h 05m	7h 25m	97%	86%

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