Why there's little rain in the desert or even none at all?

So Since cool air cannot retain as much water vapor as warmer air can, the excess water precipitates. Moisture blowing in from the ocean is effectively drained, and the air that moves down the ranges' eastern slopes is usually so dry it cannot produce any more rain in the desert

Explanation:

So Since cool air cannot retain as much water vapor as warmer air can, the excess water precipitates. Moisture blowing in from the ocean is effectively drained, and the air that moves down the ranges' eastern slopes is usually so dry it cannot produce any more rain in the desert

Equator

Explanation:

For example, the Sahara desert in North Africa doesn't get a lot of rain because it's pretty close to the equator which means it's very hot and doesn't get lots of rain.