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

Return flights

07 Dec - 19 Dec	Spirit Airlines
09 Dec - 21 Dec	Spirit Airlines
08 Dec - 21 Dec	Spirit Airlines
24 Dec - 10 Jan	Spirit Airlines
31 Dec - 05 Jan	Spirit Airlines
12 Dec - 12 Jan	Spirit Airlines
24 Dec - 11 Jan	Spirit Airlines
30 Dec - 06 Jan	Spirit Airlines
20 Dec - 27 Dec	Frontier Airlines
30 Dec - 04 Jan	Spirit Airlines
26 Dec - 12 Jan	Spirit Airlines
28 Dec - 06 Jan	Spirit Airlines
28 Dec - 04 Jan	Spirit Airlines
16 Dec - 02 Jan	Spirit Airlines

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

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 December from 336€

Return flights