The climate of a tropical rain forest is warm and humid all year long. Average annual temperatures are between 68° and 84°F (20° and 29°C), and the temperature never drops below 64°F (18°C). There is almost no seasonal change. Differences in temperature are greater between night and day than between winter and summer.
At least 80 inches (203 centimeters) of rain falls in a year, and many areas receive up to 200 inches (508 centimeters) annually. Some precipitation (rain) falls almost every day, and it may come in a thunderous downpour or in a misty shower. There is no dry season. Humidity is very high, and days are often cloudy. Although hurricanes may occur in some coastal forests, winds are normally very light. Beneath the protective cover of trees, the air may not stir at all.
In some regions near the equator that have a moist tropical climate, such as parts of India, long dry periods occur, causing trees to become deciduous (lose their leaves). Forests in these regions are discussed in the chapter titled "Deciduous Forest."
Source: "Rain Forest." U·X·L Encyclopedia of Biomes, Vol. 2. U·X·L, Detroit: 2000.