Tropical climates tend to have warm temperatures year-round, with all months having a mean temperature above 64 degrees Fahrenheit. They also receive significant precipitation, which typically exceeds 59 inches annually. Tropical climates sit 15 to 25 degrees north and south of the equator.
Desert climates are incredibly dry, however. Their annual rainfall averages less than 20 inches a year, with such deserts as Atacama in Chile receiving no rain at all certain years.
Tropical climates provide habitats for a multitude of animals. The University of Delaware estimates that 40 percent to 75 percent of all species in the world are indigenous to rainforests. Birds and animals often have brilliant colors to blend in with the bold vegetation.
Desert animals tend to be able to live long periods with little water and have scales, sandy or brown fur or feathers to protect them from the harsh climate and camouflage them. For instance, camels have humps to help them store water and lizards have thick scales.
Tall, broad-leaved plants and evergreens inhabit tropical climates. In rainforests, they form a leafy canopy. Orchids, mosses, tropical flowers and plants, and moisture-loving vegetation persists. Shade-tolerant shrubs, ferns, small trees and woody vines also do well.
Desert plants must use little water, survive in sandy or loamy soil, and weather harsh winds and sun. Cacti store water in their absorbent stems and leaves, for example.
Tropical deserts have sparse annual rainfall, but they typically are in subtropic zones, They have almost constant high pressure all year. According to Michael Ritter's "The Physical Environment," tropical deserts have the highest mean annual temperature on earth because they have high percentages of sunshine, and the sun sits at high angles. Temperatures may reach up to 120 degrees Fahrenheit. The high pressure in a tropical desert means few clouds, so heat escapes to space easily at night, cooling the desert. A tropical desert's significant source of water is an oasis.