Puerto Rico Geography, Climate & Nature

Puerto Rico is the smallest and easternmost of the Greater Antilles, a main island 177 kilometres long and 65 wide -- 13,792 square kilometres -- with Vieques, Culebra and Mona among the smaller islands around it. A mountain range runs its length in three sections: the Cordillera Central in the middle, where Cerro de Punta reaches 1,338 metres, the Sierra de Cayey in the south-east and the Sierra de Luquillo in the north-east, where El Yunque rises to 1,065 metres above the rainforest that carries its name.

The mountains make the weather and the water. The trade winds from the Atlantic strike the Luquillo range first, which is why El Yunque takes about 240 inches -- six metres -- of rain a year and why the south coast behind the mountains is dry. There are more than 50 rivers, most rising in the Cordillera Central, and 17 lakes, every one of them man-made. In the north-west the limestone has dissolved into the Northern Karst Belt, where most of the island's caves are.

The coast is where the people are: San Juan and its metropolitan area on the north shore, the ferry port of Ceiba on the east coast facing Vieques and Culebra, and the beaches all the way round.

Puerto Rico's climate is predominantly tropical rainforest, kept from being oppressive by the easterly trade winds that cross the island all year. Lowland temperatures range from 21 to 32 degrees and average near 29; the central highlands stay between 16 and 27 degrees year round and average 21, which is why the coffee country and the Cordillera Central are where the island goes to cool off. The mountains block the trade winds and create rain shadows, so the temperature and wind can change sharply within a few kilometres: El Yunque on the windward north-east takes about 240 inches of rain a year while the south coast is dry.

The rainy season stretches from April into November, mostly as afternoon showers over the mountains rather than all-day rain. The hurricane season sits inside it and peaks in September; Irma on 5 September 2017 and Maria on the 20th are the recent measure of what that can mean. December to March is the dry, busy, expensive season, and the best one.

Best Destinations by Month has the practical reading.

For an island of 13,792 square kilometres, Puerto Rico's endemic list is long: 239 plants, 16 birds and 39 amphibians and reptiles found nowhere else. The concentration is in El Yunque, more than 28,000 acres -- 113 square kilometres -- of the Sierra de Luquillo that is the only tropical rainforest in the US National Forest System and the largest block of public land on the island; the Luquillo Experimental Forest was established there in 1956 for research and for the conservation of the Puerto Rican parrot and the elfin-woods warbler.

The parrot is the emblem of what was lost and what is being held. The island's only surviving native parrot, it was confined to the primary forest of the Luquillo mountains by 1960 and has been listed as critically endangered since 1994. The coquí frogs are the emblem of what thrives: more than twenty species, thirteen of them in El Yunque, that have been on the island for over thirty million years by the fossil and genetic evidence.

Around the main island, Culebra's Tortuga Beach lies inside the Culebra National Wildlife Refuge, much of Vieques became a refuge when the Navy left in 2003, and Vieques's two bioluminescent bays, Mosquito Bay among them, are living systems that depend on dark, clean water. No species-level survey was consulted beyond the sources in the data file; the figures are indicative.

The coquí is the animal every visitor meets, by ear: males of two of the more than twenty species call their two-note name at night, loudest after rain, and El Yunque alone has thirteen species. The Puerto Rican parrot is the one almost nobody meets -- the only native parrot left, confined to the Luquillo mountains since 1960 and critically endangered since 1994 -- and the forest's research and recovery programme has been built around it since 1956.

Vieques has its wild horses on the roads and beaches, and its two bioluminescent bays; Mosquito Bay is the famous one, and the ferry company itself names it and the horses as the island's draws. Culebra's beaches are turtle country, with Tortuga Beach on the islet of Culebrita protected inside the national wildlife refuge.

The sea around the islands is warm and clear, but this page says only what its sources say about what lives in it, which is little; the dive operators on Culebra and Vieques are the people who know.