Most dry lands exist between degrees latitude on either side of the equator.

Most dry lands exist between 30 degrees latitude on either side of the Equator.
Around the 30 degrees latitude lye most of the deserts (hot deserts more specifically) in the world, and they are one of the driest places on the planet. They form around this latitude because of the movement and type of the winds in this parts of the world, they do not bring enough precipitation to this regions, thus making them dry and inhospitable places.