Costa Rica enjoys two significant seasons: wet and dry. The temperature does not fluctuate as much as the rainfall, so this will help you in deciding when to visit. Because of the topography there are many ‘micro-climates’, so what is true of San Gerardo will not be true of other parts of the country.
In addition, because of its mountain location, the temperature can be cooler than at the coast – a refreshing difference as air conditioning is unnecessary and nights are cool enough to allow for easy sleep.
Generally speaking, the dry season is from late November – May, and the wet season the opposite, October being the rainiest month. The dry season is marked by uninterrupted days of warm, sunny weather, and the wet season has daily rainfall – usually in the afternoon, that can be very heavy.
Temperatures and Rainfall in the Highlands:
FEBRUARY – Max: 28ºC Min: 21ºC, Rainfall: 61mm
MAY – Max: 31º Min: 24º, Rainfall: 109mm
AUGUST – Max: 31º Min: 24º, Rainfall: 170mm
NOVEMBER – Max: 28º Min: 20º, Rainfall: 226mm