The question is kind of backward.
The reason it's a desert is because it doesn't rain much there.
The reason it doesn't rain much in some places (which we call deserts) has to do with wind patterns and geographical features and is fairly complicated.
South
Denmark
Amazon rain forest
A desert.
It is south of the Arctic circle.
The Arctic Circle passes through the Arctic Ocean.
A polar circle is either the Arctic Circle or the Antarctic Circle.
The Arctic Circle
the Himalayas are south of the Arctic Circle
The arctic circle
No, the Arctic Circle is an imaginary line.
Reindeer are only found in the far north near the Arctic Circle.