Rainforest Characteristics
Tropical rain forests belong to a broader forest category called tropical moist forests, of which there are many different types. Forest scientists distinguish rain forests from other types by considering factors such as temperature, rainfall, length of dry season, and altitude.

Temperature
Rain forests are typically hot and steamy. The average annual temperature is 77° F. Temperature near the equator varies little over the course of a year, so rain forest temperatures are about the same year round. The average minimum monthly temperature in a rain forest is 64° F. Rain forests are not found where the temperature drops close to 32° F because their resident plants and animals are not well adapted to withstand frost. Temperature in a rain forest depends not only on distance from the equator but also on altitude. As elevation increases, nighttime temperatures go down significantly. This daily temperature variation affects forest ecology, and true rain forests typically are not found above 3,280 ft.