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, any airlines

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.


Southwest + Unitedtwo ticketsDetails →	ONT 05:30 → LAS 06:35WN 3150	3h 50m Las Vegas	LAS 10:25 → IAH 15:40UA 1711	8h 10m	100%	91%
Alaska + Unitedtwo ticketsDetails →	ONT 06:02 → SEA 08:44AS 607	3h 11m Seattle	SEA 11:55 → IAH 18:35UA 2293	10h 33m	99%	88%
American Details →	ONT 22:10 → CLT 05:48AA 2237	1h 54m Charlotte	CLT 07:42 → IAH 09:25 +1AA 1930	9h 15m	97%	88%
Southwest + Unitedtwo ticketsDetails →	ONT 09:45 → SMF 11:10WN 3166	2h 05m Sacramento	SMF 13:15 → IAH 19:10UA 1949	7h 25m	97%	86%
United Details →	ONT 06:00 → SFO 07:25UA 2363	1h 30m San Francisco	SFO 08:55 → IAH 15:07UA 2498	7h 07m	96%	85%
Delta + Unitedtwo ticketsDetails →	ONT 22:00 → ATL 05:18DL 2892	1h 47m Atlanta	ATL 07:05 → IAH 08:15 +1UA 532	8h 15m	98%	85%
Alaska Details →	ONT 12:04 → SEA 14:44AS 654	2h 49m Seattle	SEA 17:33 → IAH 23:59AS 1579	9h 55m	100%	84%
Delta + Unitedtwo ticketsDetails →	ONT 17:59 → SEA 20:50DL 4031 · flown by SkyWest	2h 59m Seattle	SEA 23:49 → IAH 06:10 +1UA 2379	10h 11m	98%	82%
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.

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