Conversation so far:
what is an area where rainfall is less than 50 cm per year
A desert is a barren area of landscape where rainfall is less than 50 cm/year.
why are deserts bad for life
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life.
how are deserts formed
Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks which consequently break in pieces.

Question: does it ever rain in the areas
Self-contained rewrite: does it ever rain in deserts