Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: Southwest’s ONT → BWI flights land within a few points of 85% on time whatever the hour.

Nonstops (seasonal or thin)


Southwest	ONT	BWI	4h 45m	85%	0.4%	281	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Baltimore on time. Total trip = scheduled departure to arrival, layover included (Baltimore is 3 h ahead of Ontario). Layovers up to 4 hours. Pick a connection for the details.


Southwest Details →	ONT 23:55 → MDW 05:40WN 3153	3h 15m Chicago	MDW 08:55 → BWI 11:45 +1WN 1355	8h 50m	100%	90%
United Details →	ONT 06:00 → SFO 07:25UA 2363	2h 08m San Francisco	SFO 09:33 → BWI 17:57UA 2664	8h 57m	98%	88%
Delta Details →	ONT 22:00 → ATL 05:18DL 2892	3h 37m Atlanta	ATL 08:55 → BWI 10:47 +1DL 801	9h 47m	100%	86%
United Details →	ONT 05:00 → DEN 08:20UA 2446	1h 26m Denver	DEN 09:46 → BWI 15:17UA 1362	7h 17m	97%	86%
American Details →	ONT 22:10 → CLT 05:48AA 2237	2h 12m Charlotte	CLT 08:00 → BWI 09:26 +1AA 1635	8h 16m	98%	84%
United Details →	ONT 18:39 → SFO 20:07UA 5624 · flown by SkyWest	2h 33m San Francisco	SFO 22:40 → BWI 07:10 +1UA 1340	9h 31m	95%	79%
Southwest Details →	ONT 05:50 → DEN 09:05WN 3144	1h 50m Denver	DEN 10:55 → BWI 16:20WN 4434	7h 35m	100%	78%
Alaska Details →	ONT 17:26 → SEA 20:06AS 575	1h 30m Seattle	SEA 21:36 → BWI 05:41 +1AS 781	9h 15m	89%	78%
Tight connection: often missed
Southwest Details →	ONT 12:40 → LAS 13:45WN 3151	50m Las Vegas	LAS 14:35 → BWI 22:10WN 2205	6h 33m	44%	19%
Southwest Details →	ONT 14:30 → DEN 17:40WN 3147	1h 25m Denver	DEN 19:05 → BWI 00:35 +1WN 1500	7h 03m	65%	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

MDW · 1h 20m · leaves 23:55 3%

IAH · 1h 12m · leaves 05:45 6%

Afternoon and evening

DEN · 1h 15m · leaves 13:18 10%

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.


Frontier F9 2275 ONT 16:04 → SEA Alaska AS 781 SEA 21:36 → BWI Connection details →	2h 38m	10h 37m	94%	84%
American AA 2237 ONT 22:10 → CLT Southwest WN 4695 CLT 07:50 → BWI Connection details →	2h 02m	8h 10m	89%	81%
Delta DL 2892 ONT 22:00 → ATL Southwest WN 4364 ATL 07:00 → BWI Connection details →	1h 42m	7h 50m	96%	79%

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