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

Return flights

04 Sep - 16 Sep	Copa
06 Sep - 16 Sep	United
08 Sep - 18 Sep	Avianca
01 Sep - 14 Sep	Avianca
05 Sep - 14 Sep	Avianca
07 Sep - 17 Sep	Spirit Airlines
26 Sep - 29 Sep	Avianca	direct
06 Sep - 18 Sep	Spirit Airlines
06 Sep - 14 Sep	Spirit Airlines
08 Sep - 17 Sep	Avianca	direct

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

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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Cheapest return flights from Boston to San Salvador in September from $228

Return flights