Which months is the best time to go to costa rica?

Question

WHEN IS IT NOT RAINING?

Answer 1

right now its not raining, rainy season is may thru november

Answer 2

It depends where you want to go.  On the Atlantic side (which is the rainiest side),  September, October and May have the least rain but on the Pacific side it is right now from December through mid-April.  The months to avoid in San Jose and on the Pacific side are August, September and October.  May June and July are not bad either.  You will get a mix of rain and sunshine.