Cheapest return flights from Seattle to San Juan in December from $278
AirHint found the following cheapest return flights from Seattle (SEA) to San Juan (SJU)
in December 2025 (see full year ).
Return flights
06 Dec
- 13 Dec
Frontier Airlines
$ 278
08 Dec
- 12 Dec
Frontier Airlines
$ 281
09 Dec
- 15 Dec
American Airlines
$ 363
04 Dec
- 08 Dec
Frontier Airlines
$ 391
11 Dec
- 14 Dec
Frontier Airlines
$ 419
10 Dec
- 14 Dec
Alaska Airlines
$ 443
22 Dec
- 31 Dec
Frontier Airlines
$ 522
21 Dec
- 25 Dec
Frontier Airlines
$ 544
22 Dec
- 06 Jan
Frontier Airlines
$ 596
29 Dec
- 05 Jan
Frontier Airlines
$ 609
03 Dec
- 26 Dec
Alaska Airlines
$ 610
23 Dec
- 31 Dec
Frontier Airlines
$ 617
26 Dec
- 01 Jan
Sun Country Airlines
$ 646
20 Dec
- 06 Jan
Sun Country Airlines
$ 646
23 Dec
- 01 Jan
Frontier Airlines
$ 668
24 Dec
- 01 Jan
Frontier Airlines
$ 698
22 Dec
- 05 Jan
Frontier Airlines
$ 726
27 Dec
- 10 Jan
American Airlines
$ 842
24 Dec
- 02 Jan
Frontier Airlines
$ 845
23 Dec
- 02 Jan
Frontier Airlines
$ 845
Also check the deals for one-way flights from Seattle to San Juan in December .
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