My favorite thing in the entire world is before a thunderstorm hits. I was just laying down on a little hill outside, watching the storm brew. My parent's neighbors probably think I'm insane. ...They might not be wrong.
The grass knows the rain is coming. You can feel it waiting for the water. The trees all shiver and tumble in the wind in anticipation. My favorite is when the temperature drops really fast, and the air is cool and moist. The underside of the clouds are that pretty slate blue gray, and little thin fingers of lightning grasp out. Then after a moment the crumbling tinker of thunder rolls out, and you can hear it echo across the valley and buildings and streets.
There's nothing better.