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

No clear winner: JetBlue’s SJU → BUF flights land within a few points of 85% on time whatever the hour.

Nonstops (seasonal or thin)


JetBlue	SJU	BUF	4h 38m	85%	1.4%	73	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


American Details →	SJU 00:59 → ORD 05:04AA 2592	1h 42m Chicago	ORD 06:46 → BUF 09:37AA 4413 · flown by Republic	8h 38m	97%	90%
Southwest Details →	SJU 05:20 → BWI 09:30WN 3717	1h 20m Baltimore	BWI 10:50 → BUF 12:05WN 762	6h 45m	98%	84%
United Details →	SJU 01:00 → EWR 05:10UA 2219	3h 15m Newark	EWR 08:25 → BUF 09:53UA 3529 · flown by Republic	8h 53m	97%	82%
United Details →	SJU 07:40 → ORD 11:53UA 2089	2h 02m Chicago	ORD 13:55 → BUF 16:41UA 2226	9h 01m	100%	81%
Delta Details →	SJU 07:30 → ATL 11:20DL 1763	2h 40m Atlanta	ATL 14:00 → BUF 16:06DL 2266	8h 36m	99%	80%
United Details →	SJU 07:20 → IAD 11:21UA 2022	1h 38m Dulles	IAD 12:59 → BUF 14:25UA 4335 · flown by CommuteAir	7h 05m	99%	79%
American Details →	SJU 14:25 → PHL 18:38AA 903	3h 42m Philadelphia	PHL 22:20 → BUF 23:53AA 5911 · flown by Piedmont	9h 28m	99%	78%
Delta Details →	SJU 07:05 → JFK 11:01DL 1854	2h 28m New York	JFK 13:29 → BUF 15:09DL 5296 · flown by Endeavor	8h 04m	98%	76%
Tight connection: often missed
JetBlue Details →	SJU 17:15 → BOS 21:22B6 762	48m Boston	BOS 22:10 → BUF 23:43B6 715	6h 28m	50%	30%

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

BWI · 1h 20m · leaves 05:20 2%

MCO · 1h 06m · leaves 02:20 15%

BOS · 1h 00m · leaves 06:00 20%

Afternoon and evening

BOS · 48m · leaves 17:15 50%

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.


JetBlue B6 562 SJU 06:00 → BOS American AA 4440 BOS 13:55 → BUF Connection details →	3h 50m	9h 44m	99%	85%
American AA 2592 SJU 00:59 → ORD United UA 2753 ORD 07:15 → BUF Connection details →	2h 11m	9h 01m	97%	83%
Delta DL 1854 SJU 07:05 → JFK JetBlue B6 2902 JFK 13:25 → BUF Connection details →	2h 24m	7h 50m	98%	75%

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