Geography and Climate

As mentioned above, the Central Valley is known for its almost “perfect” climate. Its relatively high elevation gives the region its temperate 24ºC average climate. The temperature depends on elevation, and you can feel variations from the late teens to as high as the 30s during the summer. In any case, you won’t be feeling the dry heat of Guanacaste. It is important to remember that it does get hot in some areas – like the lower-elevation Ciudad Colon and Santa Ana – and the average temperature has to incorporate a wide range of elevations and the area’s extreme geological diversity.

In most cases you will only need light summer clothing during the day. If you go out for the whole day during the rainy season be sure to take waterproof clothing or an umbrella. The afternoon downpour usually lasts for only a few hours, and if you’re on foot, keep in mind that finding an open taxi during a rainstorm is hard. The evenings are always cool and pleasant, and a light sweater, jacket or wrap is sufficient to stay comfortable. Keep in mind that the weather is almost always the same, except when a tropical depression hits one of the coasts. When that happens – a few times a year at most – the rain is more constant, perhaps heavier, and starts at odd hours, but it’s nothing compared to bad weather in other parts of the world. Also, during December, the Central Valley gets the vientos navideños, or Christmas winds – stiff, chilly breezes that herald the arrival of the dry season.

When building or selecting a place to live, you will want to take wind direction into consideration. Generally the wind blows from East to West, meaning that the San Pedro and Curridabat eastern suburbs get the benefit of much cleaner air from Cartago, while Escazú gets the polluted air picked up in San José. Air pollution can be quite a problem in downtown San Jose, what with hundreds of poorly-maintained vehicles belching diesel exhaust into the air. Fortunately, the near-constant breeze and low humidity keeps the pollution from hanging in the air too long.

The summer officially lasts from early December through Holy Week (Late March/early April). During this season, the landscape is parched a light brown, interrupted occasionally by the pink, purple and orange blossoms that bloom on certain trees during that season. Though the dry season officially ends around April, May through August still have many days of sunny weather, and even in the rainy season, it’s almost always sunny in the morning.

There are a number of protected areas in the region, which is rather fortunate, as the rest of the area is getting built out, and rather densely so. There are three national parks - the volcanoes of Poás, Barva and Irazú. There are also forest reserves in Atenas, Escazú, Puriscal and Grecia.