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 84% on time.

Nonstops (seasonal or thin)


Delta	SJU	DTW	4h 55m	85%	1.9%	324	Flying now
Spirit	SJU	DTW	4h 38m	74%few flights	0.0%	33	Not flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Detroit on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


Delta Details →	SJU 06:00 → ATL 09:50DL 1879	1h 10m Atlanta	ATL 11:00 → DTW 12:55DL 1240	6h 56m	98%	81%
JetBlue + Deltatwo ticketsDetails →	SJU 07:00 → PHL 11:01B6 1048	1h 35m Philadelphia	PHL 12:36 → DTW 14:20DL 2331	7h 22m	89%	76%
Delta Details →	SJU 12:54 → ATL 16:47DL 1757	1h 24m Atlanta	ATL 18:11 → DTW 20:14DL 1478	7h 19m	97%	73%
United Details →	SJU 07:20 → IAD 11:21UA 2022	1h 34m Dulles	IAD 12:55 → DTW 14:34UA 3495 · flown by Republic	7h 14m	99%	71%
Delta Details →	SJU 17:56 → ATL 21:54DL 1946	1h 05m Atlanta	ATL 22:59 → DTW 00:59 +1DL 2940	7h 03m	90%	64%
JetBlue Details →	SJU 08:03 → FLL 10:43B6 1754	1h 17m Fort Lauderdale	FLL 12:00 → DTW 15:10B6 790	7h 07m	87%	63%
Southwest Details →	SJU 17:15 → BWI 21:25WN 3719	1h 15m Baltimore	BWI 22:40 → DTW 00:20 +1WN 942	7h 00m	96%	63%
American Details →	SJU 15:40 → CLT 19:39AA 783	1h 07m Charlotte	CLT 20:46 → DTW 22:34AA 419	6h 54m	89%	58%

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 10m · leaves 06:00 2%

FLL · 1h 17m · leaves 08:03 13%

Afternoon and evening

ATL · 1h 05m · leaves 17:56 10%

CLT · 1h 07m · leaves 15:40 11%

MIA · 1h 11m · leaves 16:38 19%

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