What is the cheapest month to fly from Koh Samui to Seattle?

Based on current 6-month forward fare data, September 2026 is the cheapest month to fly from Koh Samui (USM) to Seattle (SEA), with fares starting from $669.

What is the lowest current fare from USM to SEA?

The lowest currently-listed fare from Koh Samui (USM) to Seattle (SEA) is $669 on 2026-09-19.

Is there a direct flight from Koh Samui to Seattle?

There is currently no non-stop service from USM to SEA. Most travellers connect through a hub airport. See our route page for current stopover options.

Cheap flights from Koh Samui to Seattle

Cheapest current fares: $669 in September 2026 on connecting flights.

Last updated August 5, 2026 · By Flightmaps Editorial

Cheapest month-by-month fares

Lowest available fare per calendar month from Koh Samui (USM) to Seattle (SEA). Refreshed daily.

Koh Samui (USM) → Seattle (SEA)

September 2026 $669
August 2026 $728

Frequently asked questions

What is the cheapest month to fly from Koh Samui to Seattle?

Based on current 6-month forward fare data, September 2026 is the cheapest month to fly from Koh Samui (USM) to Seattle (SEA), with fares starting from $669.
What is the lowest current fare from USM to SEA?

The lowest currently-listed fare from Koh Samui (USM) to Seattle (SEA) is $669 on 2026-09-19.
Is there a direct flight from Koh Samui to Seattle?

There is currently no non-stop service from USM to SEA. Most travellers connect through a hub airport. See our route page for current stopover options.

Related guides for this route

Sibling pages — full route detail, airport overviews, visa context, per-airline routes.