Arid is so dry that nothing will grow. Death Valley in California features an arid climate, which is why it's called Death Valley and not Life Valley.
Arid can also mean terribly dull or lifeless. A textbook about the climate of Death Valley might be called arid if it's written in an uninteresting way. Just like you wouldn't want to live in an arid climate, you wouldn't want to sit through an arid performance of the film-turned-musical, "Some Like it Hot."