... Costa Rica Weather...
by Infocostarica Staff

One of the most common inquiries we receive when traveling up north, especially in winter is,” What’s the weather like down there in Costa Rica”? Most people expect a pretty straightforward answer, I mean, how much variation can there be in a country about the size of West Virginia? Short answer? A lot. In more temperate zones, like the United Sates and Canada, people are accustomed to four seasons that, although predictable in their coming, include a wide range of weather conditions such as snow, freezing rain, rain, tornados and even hurricanes. Unlike temperate countries however, Costa Rica has only two seasons: The dry season from late November to mid April and the rainy season from May to mid November. That said, because of its location and geography, there are many microclimates depending on what side of the country you’re in or at what altitude. Temperatures vary primarily with elevation, not according to season. Rainfall in Costa Rica results from the interaction of the trade winds with local topography. When moisture-laden air coming in off the Caribbean Sea encounters the coastline, the difference in surface temperature between the land and the water can often trigger showers. Moving further inland the air reaches the eastern foothills of the country's mountainous backbone. As the air mass rises to pass over the barrier, it cools, and because cool air can hold less moisture than warm air, it rains, causing the middle elevations of the Caribbean-facing slopes to be the wettest areas in the country with average annual precipitation of more than 160 inches (4000 mm).

Below we have divided the country into six zones: Central Valley, North Pacific, Central Pacific, South Pacific, Caribbean and Northern Zone, in order to provide a more realistic picture of weather trends in Costa Rica at a given area and time of year. Of course, it never hurts to check with your local weatherman (or woman) before you travel.

Central Valley

The Central Valley includes parts of the provinces of San José, Cartago, Heredia and Alajuela. Like Costa Rica itself, climate in the Central Valley varies from warm and dry to humid and chilly depending on which side of the valley you are located on. To take two extremes, the western San José suburb of Pavas is located at an elevation of 3,280 ft (1,000 mts) and averages a year around temperature of 71 degrees Fahrenheit (22 Celsius) with the lowest temperatures recorded in December and January (64 F, 18 C) and the highest in March and April (80 F, 27 C). On the other side of the valley, on the foothills of the Poás Volcano and at an elevation of 6,070 ft (1850 meters), Fraijanes averages a year around temperature of 62 F (17.4 Centigrade) with the lowest temperatures recorded in December and January (53 F, 12 C) and the highest in March and April (73 F, 22.9 C). Rainfall also varies considerably. Pavas receives an annual rainfall amount averaging 77 inches (1,960 mm) with September and October recording the highest amounts and January and February the lowest. Fraijanes, on the other hand, receives 127 inches (3,230 mm) a year with September and October recording the highest amounts and February and March the lowest. Even during the rainy season however, long rainy days are rare in the Central Valley. Mornings are generally clear, followed by a few hours of heavy downpour in the afternoon. During the dry season, especially during late December and January, expect dry windy conditions with cool nights.

North Pacific

This region includes the province of Guanacaste, the western section of the province of Alajuela and the northern section of the Puntarenas Province. This is one of Costa Rica’s most visited regions as it includes some of the country’s most dazzling beaches (Tambor, Sámara and Flamingo among others). Liberia, Its main city, has an average annual temperature of 82 F (28 C) with high temperatures above 90 F (32 C) from February through April. Although this is Costa Rica’s sunniest region, you can expect regular afternoon showers from June through October – excluding a traditional dry spell in July called “veranillo” or little summer. The North Pacific has an average annual rainfall of 55 inches (1400 mm) and boasts its sunniest months from January through April.

Central Pacific

This coastal region includes parts of the provinces of Puntarenas and San José starting from the Tárcoles River down to the the Barú River. This area includes the well-visited beach communities of Jacó, Dominical, Uvita, Quepos (near Manuel Antonio National Park) and Puntarenas to the north. In Puntarenas, daytime temperatures may reach the low nineties (above 32 degrees Centigrade) throughout the year. March through May are usually considered the hottest months, although at the beaches, refreshing breezes moderate the heat. The dry season in this area lasts from about January through March, which means rain showers will occur most afternoons at other times of year.

South Pacific

Part of the province of Puntarenas, this region boasts some of Costa Rica’s most varied topography including high mountains and vast tracks of pristine rainforest located in the Osa Peninsula. This area has a very distinct dry (January to mid April) and rainy season (May through December). Temperatures near the coast do not vary much and average from the low 80’s through low 90’s (upper 20’s to low 30’s Centigrade) throughout the year. In the Valle del General (General Valley) expect more moderate temperatures (high 70’s to low 80’s) and morning temperatures as low as 50 degrees Fahrenheit (10 C) in the higher elevations. Precipitation varies widely from 120 inches (3000 mm) in the Valle del General to 200 inches (5000 mm) in the Osa Peninsula. The rainiest month in this area tends to be October, while the driest month is usually February.

Caribbean

This region includes the province of Limón and is the most humid and rainiest area of Costa Rica. Attractions here include Tortuguero National Park, Cahuita and scenic white water rivers. Due to the constant humidity blown in from the Caribbean Sea, downpours occasionally last for days. Temperatures in the coastal areas and southern Talamanca Mountains average in the low 80’s (upper 20’s Centigrade), with May, June and October being the hottest months. Slightly lower temperatures may be experienced from December through February. Although it rains throughout the year, you can usually count on clearer conditions during September and October (the rainiest months in the Central Valley). In the Turrialba region (about an hour and a half from San José), the rainiest months are June and November. Expect temperatures here to be slightly cooler (upper 70’s to low 80’s year around).

Northern Zone

The rural and relatively less populated northern region includes parts of the provinces of Guanacaste, Alajuela and Limón. Temperatures encountered vary depending on altitude. In the higher elevations, temperatures average in the low to mid 60’s (mid to upper teens Centigrade) while in the lowlands, such as in San Carlos, expect temperatures in the upper 70’s to low 80’s (mid to upper 20’s Centigrade) year around. Like the Central Valley, the months of April and May are considered to be the hottest while December and January the coolest. Lowland rainfall averages about 100 inches (2,500 mm) a year while in the mountains expect to receive 140 inches (3,500 mm) or more. Attractions in the area include the active Arenal Volcano and world famous Monteverde Cloud Forest Reserve.