Cheapest return flights from Islip to San Juan in January from $237

AirHint found the following cheapest return flights from Islip (ISP) to San Juan (SJU) in January 2026 (see full year).

Return flights

30 Jan - 07 Feb Frontier Airlines
30 Jan - 04 Feb Frontier Airlines
30 Jan - 05 Feb Frontier Airlines
26 Jan - 11 Feb Frontier Airlines
26 Jan - 28 Jan Frontier Airlines
26 Jan - 31 Jan Frontier Airlines
22 Jan - 29 Jan Frontier Airlines
26 Jan - 30 Jan Frontier Airlines
23 Jan - 31 Jan Frontier Airlines
25 Jan - 29 Jan Frontier Airlines
23 Jan - 28 Jan Frontier Airlines
23 Jan - 29 Jan Frontier Airlines
23 Jan - 30 Jan Frontier Airlines
25 Jan - 30 Jan Frontier Airlines
26 Jan - 09 Feb Frontier Airlines
30 Jan - 01 Feb Frontier Airlines
30 Jan - 02 Feb Frontier Airlines
25 Jan - 01 Feb Frontier Airlines
29 Jan - 02 Feb Frontier Airlines
29 Jan - 01 Feb Frontier Airlines

Also check the deals for one-way flights from Islip to San Juan in January.

Powered by

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in San Juan

Cheap car rent in San Juan

Feel free to contact us with any feedback or request another flight research.