The best time to travel to Costa Rica is from December to April, even better between January and March.
The climate of Costa Rica is mainly tropical: the dry season from December to April and the wet season from May to November.
Temperatures are high throughout the year except for the mountainous areas where there are strong temperature changes between day and night.
May, June, July and August are wet months, especially in the central mountainous area and you may encounter some tropical storms, which is a natural spectacle that is worth seeing.
The region of Guanacaste is the driest in the country, while in the South Pacific it rains more, especially in the rainforest of the Osa peninsula.
The central area is the cooler one, being mountainous.