Costa Rica’s climate: an enigma to be solved

Costa Rica’s climate is an enigma. Weather is already unpredictable in the tropics. Now imagine it in a rugged country like Costa Rica, surrounded by water but not an island.

Yet it’s thanks to this random and unpredictable climate that this little piece of land is the green paradise that it is. What we think of as bad weather elsewhere in Costa Rica is in fact the staging of the water cycle in a tropical system that is still very well preserved.

Costa Rica’s climate is complicated, of course. But as Costa Rica experts, we’re here to help you make sense of it. In this series of articles, we’ll explore Costa Rica’s climate. After these 3 articles, we’ll have a clearer idea of how the water cycle behaves in this green paradise.

Dry season and humid season

We all knew that already. In Costa Rica, there are two seasons: the wet season, when it rains a lot, and the dry season, when it rains less. On the one hand, the dry season runs from December to May and the wet season from May to November. We’ve always known that.

However, what nobody ever told you is that this magic formula about Costa Rica’s climate only applies to the part of the country under the influence of the Pacific Ocean, not to the whole territory. In fact, the Caribbean coast and the regions bordering it behave in the opposite way to the Pacific coast.

The Pacific coast has a positive humidity gradient between north and south. This applies, for example, to the well-known Pacific city of Tamarindo.

Costa Rica’s climate: the whims of mountains and volcanoes

Costa Rica is a land of mountains and volcanoes. They all run from northwest to southeast, like a spine. A spine forged millions of years ago to link North and South America. It used to be a single sea, a single system. After the emersion of these territories, two distinct and independent environments were born.

These mountains and volcanoes range from 100 to 500 m for the oldest lands, and from 500 to 3820 m for the youngest. Not only do they divide Costa Rica’s climate in two, they also create a series of altitude levels where life thrives and where the water cycle behaves differently according to altitude.

Finally, these mountains and volcanoes have one side facing the Pacific and the other the Caribbean. Depending on which side you visit, you’ll appreciate one influence or the other, even if you’re in the same tourist region.

Costa Rica is crossed from north to south by a chain of mountains and volcanoes that divide the country into 2 halves

Costa Rica’s climate: humidity gradients on the Pacific coast

Let’s talk about the Pacific humidity gradient. Let’s imagine we take a private flight from Liberia to Puerto Jimenez on a sunny morning in March. After take-off, we see a dry, sometimes desert-like landscape. Further south, near Carara National Park, we see forests of green, deciduous and dry trees. And already to the south, near Marino Ballena Park, we’ll see nothing but green, green as far as the eye can see. In Liberia, as in Puerto Jimenez, it was probably sunny all day on the March day we took this flight. However, in the rainy season for the Pacific, it’s a different story.

The Pacific coast has a positive humidity gradient between north and south

In a future article, we’ll talk in more detail about each influence and its behavior throughout the year.

For real-time information on the climate in Costa Rica, visit the website of the National Meteorological Institute of Costa Rica.

For now, we want to know what you think: did you already know about the influence of mountain systems in Costa Rica?