AirHint found the following cheapest return flights from Washington (IAD) to San Jose (SJO) in January 2026 (see full year).

Return flights

27 Jan - 31 Jan	Volaris El Salvador
07 Jan - 12 Jan	American Airlines
06 Jan - 12 Jan	American Airlines
29 Jan - 02 Feb	American Airlines
24 Jan - 29 Jan	Avianca
24 Jan - 29 Jan	Avianca	direct
19 Jan - 27 Jan	Avianca	direct
12 Jan - 19 Jan	Frontier Airlines
13 Jan - 19 Jan	Avianca
17 Jan - 19 Jan	Avianca
12 Jan - 22 Jan	Frontier Airlines

Also check the deals for one-way flights from Washington to San Jose in January.

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 Washington to San Jose in January from $229

Return flights