What is the defining factor of a dry climate?

A dry climate is defined by yearly precipitation that is less than the loss of water through evaporation. Dryness is not only related to annual rainfall total but is also a function of evaporation, which is closely dependent on temperature.

In a dry climate, the rainfall ranges between 30 inches and 50 inches per year. The perfect example of a dry climate is a tropical savanna. These areas have two seasons in a year: namely dry and wet seasons. This kind of climate is found in Africa, India, Malaysia, Australia and northern parts of South America with average temperatures at or above 64 °F.