It all depends on your schedule! Costa Rica is a tropical country, so the warm temperature is more or less consistent all year-round. There is a marked dry season and a rainy season (the latter is also referred to as the “green season”).
Here’s a brief description of them each:
The dry season occurs from December to April, and typically means sunny days throughout those five months, although there are occasional rains. Costa Rica receives most of its visitors during this time of year partly because of the higher likelihood of having sunny days that won’t interfere in any outdoor plans, but mostly because it coincides with colder weather in more northern latitudes, making people search for warmth in the tropics. This means the dry season is also the high season in Costa Rica, which inevitably makes prices higher throughout the country. This rise in prices is particularly true in two marked time frames within the dry season: 1) Christmas and New Year’s and 2) Easter and Spring Break.
During these dates tourists and locals flee the city and flock to the beaches and other natural hot spots. Why wouldn’t they? The weather is beautiful and they’re off work for the holidays! So if you like meeting lots of fellow travelers during your vacations, this is the time of year for you to come.
The rainy season or green season gets its second name because during this time (May through November) the whole country starts looking a lot greener. This is especially notorious in the Guanacaste province, where the dry season turns the forest brown, and the rainy season completely turns its face around. With that description you would think that there must be lots of rain falling –and it’s true!- but the great thing is most of it falls in the evening and at night, resulting usually in glorious sunny days to enjoy the outdoors and wonderfully cool evenings to unwind and relax. Of course, just as any day throughout the year in Costa Rica, there is also the chance of rain falling throughout the day. If you picture your vacation with less people and reduced prices, the green season is your perfect pick.
A note on wildlife and weather as a deciding factor: Wildlife and weather are ultimately unpredictable and we cannot guarantee that you’ll have no rain and see a wild tapir depending on the season you choose. However certain patterns are worth noting when deciding when to come, if you wish to see something specific. As an example, the green season –particularly August through October- is the best time to spot the humpback whales and their calves in Costa Rica!