December to April are the driest months in Costa Rica, although rain is common throughout the year, especially on the Caribbean coast. May to November are wet, although mornings are usually sunny and rains come in the afternoon. Costa Rica is greenest towards the end of the rainy season.
Temperatures range from very hot on the Pacific and Caribbean coasts - highs of over 30ºC throughout the year - to cool in the mountains. In Monteverde, temperatures can drop to lower than 10ºC at night.