Tropical Moist (Group A) climates are found in a band about 15º to 25º N and S of the equator. What climate characteristics is the tropical moist climate group likely to have?
- Temperature: Intense sunshine; each month has an average temperature of at least 18 ºC (64 ºF).
- Rainfall: Abundant, at least 150 cm (59 inches) per year.
The wet tropics have almost no annual temperature variation and tremendous amounts of rain fall year round, between 175 and 250 cm (65 and 100 inches). These conditions support the tropical rainforest biome. Tropical rainforests are dominated by densely packed, broadleaf evergreen trees. These rainforests have the highest number of species or biodiversity of any ecosystem.
Tropical Monsoon (Am)
The tropical monsoon climate has very low precipitation for one to two months each year. Rainforests grow here because the dry period is short, and the trees survive off of soil moisture. This climate is found where the monsoon winds blow, primarily in southern Asia, western Africa, and northeastern South America.
Tropical Wet and Dry
The tropical wet and dry climate lies between about 5o and 20o latitude, around the location of the ITCZ. In the summer, when the ITCZ drifts northward, the zone is wet. In the winter, when the ITCZ moves toward the equator, the region is dry. This climate exists where strong monsoon winds blow from land to sea, such as in India.
Rainforests cannot survive the months of low rainfall, so the typical vegetation is savanna. This biome consists mostly of grasses, with widely scattered deciduous trees and rare areas of denser forests.