Which of the following best defines a Desert climate?

A Desert climate is characterized by extremely low annual precipitation, specifically receiving less than 10 inches of rain each year. This lack of moisture is essential in distinguishing desert climates from other climate types, such as temperate, tropical, or humid climates, which typically receive significantly more rainfall. The limited rainfall significantly affects the vegetation and wildlife in these regions, often resulting in sparse plant life and adapted species that can survive in arid conditions.

The other choices do not accurately define a desert climate. Higher rainfall figures, such as those noted in the first option, are characteristic of more humid or temperate regions. The second option describes climates that are more moderate, which do not align with the fluctuations typically found in desert environments. Lastly, the fourth option about high humidity is contradictory to desert climates, which are defined by their dryness and low humidity levels. Thus, the defining characteristic of receiving less than 10 inches of annual rainfall correctly identifies a Desert climate.