Costa Rica is a Central American country, 51,100 km² with population of 5.1 million. The country occupies the famous Central American isthmus between Nicaragua (north) and Panama (south), with the Caribbean Sea (east) and Pacific Ocean (west) coastlines. Costa Rica famously abolished its military in 1948 (one of the few countries without armed forces) and channeled the savings into education and healthcare — producing one of Latin America's highest literacy rates, longest life expectancies, and most stable democracies. The country is one of the world's most biodiverse — Costa Rica contains 5% of all species on Earth despite being just 0.03% of Earth's land area, with 28 national parks and 26% of land area under environmental protection. The famous "Pura Vida" ("Pure Life") cultural philosophy reflects extensive Costa Rican attitudes toward life balance, environmental consciousness, and the famous Tico/Tica hospitality. Costa Rica is one of the world's top eco-tourism destinations.
Major destinations include Arenal Volcano and La Fortuna (the famous 1,633 m active volcano with extensive hot springs including Tabacón and Baldi, the famous La Fortuna Waterfall, and extensive canopy zip-line tours), Monteverde Cloud Forest (the famous misty montane forest with extensive hanging bridges, the famous Resplendent Quetzal viewing, and the famous Monteverde Cheese Factory), Manuel Antonio National Park (the famous compact national park combining rainforest with white sand Pacific beaches — three-toed sloths, white-faced capuchins, and squirrel monkeys readily visible), Corcovado National Park on the Osa Peninsula (National Geographic called this "the most biologically intense place on Earth" — Costa Rica's most remote and primary rainforest), Tortuguero National Park (the famous Caribbean-coast turtle nesting destination accessible only by boat or small plane), Cahuita National Park and Puerto Viejo (the famous Caribbean coast with extensive Afro-Caribbean culture, calypso music, and reggae influence), the famous Tamarindo, Santa Teresa, and Nosara surf beaches on the Pacific (some of the world's best beginner-to-advanced surf), the famous Rio Celeste (the famous turquoise river created by mineral chemistry), the famous Poás Volcano and Irazú Volcano accessible from San José, the famous Nicoya Peninsula (one of the world's five "Blue Zones" — areas with exceptional longevity), Tortuguero's green sea turtle nesting (July-October), and the famous Talamanca Mountains. The country has two seasons that are emphatic: dry (December through April) and green (May through November). The country has two coasts with different microclimates, mountains that catch rain when the lowlands don't, and a Caribbean side that operates on its own calendar.
Quick verdict
Best overall: December through April. Dry, sunny, easy logistics. Mid-December through mid-April is peak season.
Best for budget travelers: May, June, and September. "Green season" but mostly mornings sunny, afternoons rainy. 30-50% lower prices than dry season.
Best for wildlife: Late November through January. Migratory birds, active mammals, abundant rain forest after the wet season.
Best for the Caribbean coast (Puerto Viejo, Cahuita, Tortuguero): September and October — the rest of the country is wet, but the Caribbean has its driest weeks then.
Avoid if you can: Late September through November on the Pacific (heaviest rain). The week between Christmas and New Year (most expensive of the year).
Dry season (December to April): peak everything
This is when Costa Rica's tourism infrastructure is built for. The Pacific coast is reliably sunny — Manuel Antonio, Tamarindo, Santa Teresa all see almost no rain. The Central Valley (San Jose, Alajuela) is warm and dry. Arenal and the cloud forests of Monteverde still get afternoon mist but the days are bright.
December starts gradually as the rains taper. The first half of December is shoulder — lower prices, occasional showers, lush green from the just-ended rainy season. After December 15, prices spike sharply as Christmas-New Year peak season hits. The window from December 22 through January 5 is the most expensive in the country.
January through March is full peak dry season. Temperatures along the Pacific coast climb to 30-33 °C; the Central Valley stays at a more comfortable 24-28 °C; Arenal mornings can be cool at 16-19 °C. By March-April the dry-side Pacific is genuinely brown and crunchy underfoot.
Green season (May to November): the cheaper, lusher alternative
May is the start of the rains but the rain pattern is usually predictable — bright sunny mornings followed by afternoon thunderstorms. Most travelers find this rhythm easy to plan around. May through July is what locals consider the "best" green season because rains are still moderate.
September and October are the wettest months. The Pacific side can see all-day rain. Trails wash out, roads to remote areas can flood, and some lodges in the southern Pacific (Osa Peninsula) close briefly. This is also the cheapest period of the year — hotel rates drop 40-50%.
The Caribbean coast operates on the opposite calendar. While the Pacific is drowning in September-October, the Caribbean has its driest, sunniest weeks. September and October are excellent for Puerto Viejo, Cahuita, and the lowland Tortuguero.
November is transitional. The Pacific is still wet through the first half; by mid-to-late November the rains taper rapidly. Late November is one of the great underrated travel windows.
The two-coast split, explained
The mountainous spine of Costa Rica creates two distinct climatic zones. The Pacific gets clear seasons. The Caribbean is wet most of the year, with brief dry windows in February-March and again in September-October.
Pacific coast and lowlands (Tamarindo, Santa Teresa, Manuel Antonio, Osa Peninsula): Dry December-April. Wet May-November. Best months: January-March.
Caribbean coast (Cahuita, Puerto Viejo, Tortuguero): Wet most of the year. Driest weeks usually late February through April, and September.
Cloud forests (Monteverde): Mist year-round. Less rain December-April but still expect cloud cover.
Arenal area: Wetter than the Pacific coast but drier than the Caribbean. Morning skies often clearest. Best volcano views: January-March, mid-mornings.
Wildlife-specific timing
Sea turtle nesting (Tortuguero): Green sea turtles July-October. Leatherbacks March-July on the Caribbean.
Whale watching (south Pacific): Humpback whales July-October (southern migration) and December-March (northern migration).
Quetzal: Best March-May in San Gerardo de Dota.
Resident birds: December-February brings migratory species in addition to year-round residents.
Frogs and reptiles: Wet season (May-November) is much more active for amphibians.
Festivals & cultural events
Fiestas Palmares (mid-January): The country's biggest annual party — 10-day festival with bullfights, concerts, parades, and extensive food culture.
Envision Festival (late February-early March): Major transformational music and yoga festival in Uvita.
Día de los Boyeros / Ox-Drivers' Day (second Sunday of March): Traditional rural celebration.
Holy Week (March-April): Costa Ricans head to the beach; coasts packed, San José and inland quiet.
Labor Day (May 1): National holiday.
Festival of the Diablitos (early February, Boruca): Indigenous celebration with traditional masked dances.
Guanacaste Day (July 25): Commemorates 1824 annexation of Guanacaste province.
Virgen de los Ángeles / La Negrita (August 2): Major pilgrimage to Cartago — Costa Rica's most important religious celebration with extensive pilgrim walks.
Mother's Day (August 15): Major family celebration.
Independence Day (September 15): Major national celebration with extensive school-children parades.
Día de las Culturas / Cultures Day (October 12): Celebrating cultural diversity.
Limón Carnival (mid-October): Major Afro-Caribbean cultural celebration.
Tope and Carnival (late December): Major year-end horse parades and celebrations in San José.
Cultural and practical notes
Spanish is the official language with English widely spoken in tourism contexts. Costa Rican colón (CRC) is the currency, though USD widely accepted in tourism. Tipping standard 10% (often included as service charge). The famous Costa Rican coffee — particularly from Tarrazú and Naranjo regions — is among the world's best with extensive coffee tour programming. The famous "Gallo Pinto" (rice and beans with vegetables) is the national breakfast dish. The country has the famous Blue Zone — the Nicoya Peninsula is one of the world's five "Blue Zones" where residents commonly live to 100+. The famous "Tico" and "Tica" reflect Costa Rican slang for residents.
Practical considerations
Juan Santamaría International Airport (SJO) near San José is the main international gateway; Daniel Oduber International Airport (LIR) in Liberia serves Pacific coast destinations directly. Direct flights from major US cities, Canada, Latin America, and seasonally from Europe. The famous "domestic flights" via Sansa and Nature Air provide rapid access to remote destinations. Rental cars work well; 4WD strongly recommended for many beaches and trails (most rentals are manual transmission). The famous Pan-American Highway runs through Costa Rica. The famous "two-week minimum" for combining Pacific + Caribbean + Arenal + Monteverde reflects significant internal travel times despite small country size.
Traveler-type advice
First-time visitors (Pacific + Arenal): January through early April.
Caribbean coast travelers: September or February-March.
Budget travelers: Late May or November.
Surfers (Pacific): South swells April-October; north swells November-March.
Wildlife photography travelers: Late November through January.
Honeymoon / relaxed beach travelers: Late November or early December.
Family travelers: December-April.
Adventure travelers (zip-line, white-water): December-April.
Yoga / wellness retreat travelers: Year-round; January-March for combined dry weather plus retreat programming.
Coffee culture travelers (Central Valley): November-March for harvest tours.
Eco-tourism travelers: November-April for major national parks; late November for combined lush green plus dry conditions.
Bottom line
Costa Rica is one of the few major tropical destinations where the green season is genuinely worth considering. Rain is predictable and contained to afternoons through most of it; mornings are bright; landscapes are at their lushest. The single most important timing decision is matching your coast to your month: never plan a Pacific dry-season experience on the Caribbean, and never expect Pacific rains on the Caribbean during its own dry window. Allow 10-14 days for combined Pacific + Arenal + Monteverde + Caribbean; longer for comprehensive Costa Rica including Osa Peninsula.