How much rainfall does the Arabian Desert usually receive each year?

Rainfall throughout the Arabian Desert is generally scarce, averaging less than 4 inches (100 mm) per year. However, annual precipitation levels can vary significantly, ranging from 0 to 20 inches (0 to 500 mm) depending on the specific location.1

In broader parts of the Arabian Peninsula that are beyond the reach of the Indian Ocean monsoon, rainfall typically averages between 3 and 4 inches (77 to 102 mm) annually. While these areas are characterized by their aridity—with droughts sometimes lasting several years—the region can experience occasional, intense, and torrential rains that lead to flash floods in the wadis. In the southwest and south, the influence of the monsoon can increase precipitation levels by fourfold or more.2