Any climate you could want, jammed into the area 1/2 the size of Nebraska.
I didn't take the tourist route, but went with a friend who was born and has family there. We traveled through almost half of the north west section of Costa Rica from the north east corner to the south west and found just about every climate the US has in spring/summer all packed into this relatively small area. Cool and breezy, hot and humid, hot and dry even down right cold. I have my preferences, but everyone has their own. If you like to see a lot of green and mountains,... you can find a climate that fits you in Costa Rica.