what is rain?
I know AZ is weird, so here you go.
Imagine those sparsely spaced white fluffy clouds covering the entire blue sky, darkening it to a dull gray (or Cosmic Blue, if you prefer). Then imagine the smell of freshly cut grass (green plants people in the rest of the Country have in their yards) and water starts falling out of the sky.
It's really amazing, I think everyone should experience it at least once.