Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Bangkok to Yakima as you normally would.
For a flight from Bangkok to Yakima, you will be flying into Yakima Air Terminal. Yakima Air Terminal (YKM) is just 4.7 km from the centre vof the city. Yakima Air Terminal is the only Yakima airport and it handles 0 inbound flights from Bangkok per day. 0 airlines have flights to Yakima Air Terminal from Bangkok on a regular basis.