Florida Keys - Climate

Climate

The climate is tropical (Köppen climate classification Aw), and the Keys are the only frost-free place in Florida. There are two main "seasons": hot, wet, and humid from about June through October, and somewhat drier and cooler weather from November through May. Many plants grow slowly or go dormant in the dry season. Some native trees are deciduous, and drop their leaves in the winter or with spring winds.

The Keys have distinctive plant and animals species, some found nowhere else in America, as the Keys define the northern extent of their ranges. The climate also allows many imported plants to thrive. Nearly any houseplant known to commerce, and most landscape plants of the South, can thrive in the Keys climate. Some exotic species which arrived as landscape plants now invade and threaten natural areas.

The native flora of the Keys is diverse, including members of both temperate families, such as red maple (Acer rubrum), slash pine (Pinus elliotti var. densa) and oaks (Quercus spp.), growing at the southern end of their ranges, and tropical families, including mahogany (Swietenia mahagoni), gumbo limbo (Bursera simaruba), stoppers (Eugenia spp.), Jamaican dogwood (Piscidia piscipula), and many others, which grow only as far north as 25 or 26 degrees north latitude.

Several plants that are popularly thought of as exemplifying Keys landscapes are in fact not native. These include coconut palm, bougainvillea, hibiscus, and papaya.

The well-known and very sour Key lime (or Mexican lime) is a naturalized species, apparently introduced from the Yucatán Peninsula of Mexico, where it had previously been introduced from Malaysia by explorers from Spain. The tree grows vigorously and has thorns, and produces golf-ball-size yellow fruit which is particularly acidic (even in highly alkaline coral soil) and uniquely fragrant. Key lime pie gets its name from the fruit.

The Keys are also home to unique animal species, including the Key deer, protected by the National Key Deer Refuge, and the American crocodile. About 70 miles (110 km) west of Key West is Dry Tortugas National Park, one of the most isolated and therefore well-preserved in the world. The name derives from the fact that when Spanish explorers arrived no fresh water could be found, and the small hump-shaped islands look like tortoise (tortuga in Spanish) shells from a distance.

The waters surrounding the Keys are part of a protected area known as the Florida Keys National Marine Sanctuary.