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


United	ORD	SJU	4h 56m	80%	0.3%	665	Flying now
American	ORD	SJU	4h 42m	73%	1.6%	429	Flying now
Frontier	ORD	SJU	5h 00m	63%	7.3%	41	Flying now
Spirit	ORD	SJU	4h 41m	63%	7.6%	263	Not flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach San Juan on time. Total trip = scheduled departure to arrival, layover included (San Juan is 1 h ahead of Chicago). Layovers up to 4 hours. Pick a connection for the details.


United Details →	ORD 08:51 → IAH 11:51UA 535	3h 12m Houston	IAH 15:03 → SJU 20:38UA 701	10h 47m	100%	91%
American Details →	ORD 05:00 → MIA 09:09AA 2984	2h 08m Miami	MIA 11:17 → SJU 14:12AA 2584	8h 12m	100%	90%
United Details →	ORD 05:00 → DEN 06:42UA 2666	3h 01m Denver	DEN 09:43 → SJU 17:38UA 1339	11h 38m	100%	83%
American Details →	ORD 05:07 → CLT 08:10AA 2842	2h 53m Charlotte	CLT 11:03 → SJU 14:50AA 783	8h 43m	97%	81%
United Details →	ORD 17:45 → IAH 20:50UA 1954	3h 06m Houston	IAH 23:56 → SJU 05:29 +1UA 1497	10h 44m	96%	81%
American Details →	ORD 06:10 → MIA 10:22AA 1380	2h 41m Miami	MIA 13:03 → SJU 15:47AA 2581	8h 37m	99%	80%
Delta Details →	ORD 06:35 → ATL 09:41DL 1247	3h 25m Atlanta	ATL 13:06 → SJU 16:46DL 1946	9h 11m	98%	79%
Delta Details →	ORD 06:05 → JFK 09:26DL 5741 · flown by Republic	3h 04m New York	JFK 12:30 → SJU 16:29DL 1961	9h 24m	96%	78%
Tight connection: often missed
United Details →	ORD 20:02 → IAH 22:59UA 2813	57m Houston	IAH 23:56 → SJU 05:29 +1UA 1497	8h 27m	52%	43%
American Details →	ORD 13:25 → DFW 15:59AA 1120	1h 53m Dallas-Fort Worth	DFW 17:52 → SJU 23:50AA 702	9h 25m	74%	43%
Frontier Details →	ORD 07:52 → FLL 12:12F9 2205	1h 05m Fort Lauderdale	FLL 13:17 → SJU 16:05F9 3018	7h 13m	71%	37%

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

ATL · 1h 12m · leaves 05:30 7%

DEN · 48m · leaves 07:05 13%

MIA · 55m · leaves 06:10 13%

Afternoon and evening

IAH · 57m · leaves 20:02 48%

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 284 ORD 06:00 → MCO Southwest WN 1465 MCO 12:10 → SJU Connection details →	2h 30m	8h 05m	100%	88%
United UA 1643 ORD 09:12 → MCO Southwest WN 2703 MCO 15:25 → SJU Connection details →	2h 12m	8h 13m	98%	82%
United UA 425 ORD 07:12 → ATL Delta DL 1946 ATL 13:06 → SJU Connection details →	2h 39m	8h 34m	100%	82%

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