Cheapest return flights from Boston to San Juan in September from $168

AirHint found the following cheapest return flights from Boston (BOS) to San Juan (SJU) in September 2025 (see full year).

Return flights

25 Sep - 28 Sep Frontier Airlines
14 Sep - 21 Sep Frontier Airlines
18 Sep - 21 Sep Frontier Airlines
06 Sep - 14 Sep Frontier Airlines
19 Sep - 22 Sep Frontier Airlines
17 Sep - 21 Sep Spirit Airlines
01 Sep - 07 Sep Spirit Airlines
18 Sep - 22 Sep Frontier Airlines
15 Sep - 22 Sep Frontier Airlines
17 Sep - 22 Sep Spirit Airlines
17 Sep - 08 Oct Spirit Airlines
23 Sep - 08 Oct Spirit Airlines
26 Sep - 08 Oct Spirit Airlines
24 Sep - 08 Oct Spirit Airlines
27 Sep - 08 Oct Spirit Airlines
28 Sep - 08 Oct Spirit Airlines
29 Sep - 08 Oct Spirit Airlines
17 Sep - 06 Oct Spirit Airlines
23 Sep - 06 Oct Spirit Airlines
26 Sep - 06 Oct Spirit Airlines

Also check the deals for one-way flights from Boston to San Juan in September.

Skyscanner

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.

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