Deserts - Locations
On the Western Side: Cold ocean currents exit off the western sides of continents. Winds blowing over these currents less their moisture over the sea and are dry by the time they get to land
In the interior of Continents: Winds blowing over continents are dry by the time they get to the interior of continents.
The leward side of mountains: Moisture carrying winds are blocked by one side (windward) of tall mountains. The other side (leeward) is consequently dry and deserts may be formed there. As the air has risen, cooled and condensed to form rain. When it sinks on the leeward side, it is then dry.
On the tropical lines of latitude: Warm air that moves from the Equator, descends over the tropics ( desert regions ) meaning clouds cant form.