The Great Basin experiences very low and sporadic rainfall due to its arid climate and the rain shadow effect created by surrounding mountain ranges.

Rainfall in the Great Basin is minimal, often averaging less than 10 inches annually. This lack of rainfall is a result of its geographical location and the rain shadow effect, where moisture is blocked by surrounding mountain ranges, preventing regular precipitation. The region's rainfall is not evenly distributed and tends to be sporadic, with some areas receiving almost no rain for long periods. This makes it a challenging environment for sustaining large-scale agriculture and vegetation.