What to Expect
The climate in different areas of the country can be quite different, especially with the given time of year. Each region is listed in full detail on this site, but here are the general expectations.
Guanacaste (Liberia, Tamarindo, Playa del Coco) – Lowlands, Hot, Dry Forest climate
Nicoya Peninsula (MalPais, Tambor, Montezuma, Samara) – Lowlands, Hot, Dry Forest climate
Central Pacific (Puntarenas, Manuel Antonio, Jaco) – Lowlands, hot and humid, Rain Forest
South Pacific (Osa Peninsula, Dominical, Corcovado) –Lowlands, hot and humid, Rain Forest
Northern Lowlands (Arenal and Sarapiqui Valley) – Hot, cooler at night, Rain Forest
Central Highlands (Monteverde,San Ramon, Tilaran) – Cloud Forest, moderate temperatures, very cool at night
Central Valley (San Jose, Grecia, Santa Ana) – Highlands, mild climate, cool at night
South Central (San Gerado de Dota, La Amistad International Park) – Mild climate
Caribbean Coast (Puerto Viejo de Limon, Tortuguero) – Lowlands, Hot and Humid, Rain Forest
The rainy season, or "green" season, spans from May to mid-November. This is winter to Costa Ricans. The dry-season takes up the rest of the year and is referred to by Costa Ricans as "verano", which means summer. The length of the dry season can vary by region, with the Guanacaste region dry-season lasting several weeks longer than some of the other regions. In general, the higher up you go the more rain there will be and the cooler the temperatures may be. If you are accustomed to cooler temperatures it can feel relieving at times to go to a cooler area like Monteverde to get accustomed to the tropics or to take a break from the heat of the coast.
The Central Valley enjoys the best climate in the country, with an average temperature of 72 degrees and the influence of a cool coastal breeze. The Caribbean has its own type of climate and is generally always hot and humid but not always sunny, without the distinct wet and dry seasons that the Pacific side of Costa Rica has.
December and January are probably the nicest times of year for weather because the countryside is still green from the rainy season, the rivers still have moderate to high flow, and the weather is generally sunny. Days during the rainy season often start nice and sunny with breath-taking rains coming at a predictable time later in the day and evening. It can be smart to start an active day early during this time of year and then sip a cup of coffee and watch the pouring rains later in the day from under cover somewhere with a view. Remember, the vast differences in climate within the relatively small country of Costa Rica is what gives it so many distinctly different and beautiful ecosystems.
