Costa Rica is divided in half by an alpine spine through the middle of the country. The Pacific side has dry forests while the Caribbean side has wet, humid rainforests. Like the country's natural regions, the year is divided into two, with a rainy and dry season.

The rainy season lasts from May to November. Expect plenty of rain, especially when there is a hurricane somewhere else in the Caribbean. The dry season lasts from December to April and is the most popular tourist season.

Throughout both seasons, there is little variation in coastal temperatures with most days being somewhere in the range of 77°F (25°C) to 90°F (30°C). The mountainous areas in the centre of the country are significantly colder than this because of their higher altitude.

Unlike many other countries on the Caribbean Sea, Costa Rica is at little risk of hurricanes. Earthquakes and volcanic activity are more pressing environmental hazards and, while rare, have resulted in fatalities in the past. Expats should therefore make sure they are up-to-date and well-informed about the risk of natural disasters in Costa Rica.