9. What to wear in Costa Rica
The dry season, runs from December to April. It is during this season that the highest temperatures occur, therefore, light clothing is recommended except in December and January, when the North and Northeast tradewinds blow, causing the temperatures to decrease during the late afternoon and evening. The use of sweaters or light coats is recommended for these months. This season is characterized by unclouded skies, warm temperatures at mid-day and cool nights.
The rainy season presents longer cloudy periods and heavy tropical rains from May to October, with a small spring like period at the end of July, and the beginning of August. During the rainy season is recommended to carry a raincoat and an umbrella.
In the coastal areas of both the Caribbean and Pacific slopes in both the dry and rainy seasons, temperatures are warm (24 C to 32 C.). It is wise to be careful of dehydration and exposure to sunlight, which is especially strong in the coastal areas. The use of a hat and skin protection creams or oils as well as sunglasses is advised.
In the higher parts of the country, volcanoes and mountains, temperatures are cool, between 6 C and 14 C degrees. A warm jacket or coat and a hat should be worn. Costa Ricans dress informally and it is not necessary to dress up to go to a theater or out to dinner.