Answer:
I am seen in the water. If seen in the sky, I am in the rainbow, a jay's feather, and lapis lazuli.
I tremble at each breath of air, and yet can heaviest burdens bear.
My thunder comes before the lightning. My lightning comes before the clouds. My rain dries all the land it touches.
Jack and Jill when up the hill jack fell down
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. The wind is my lover, one-legged am I. Name me and see me at home in the sky.
What never gets any wetter no matter how hard it rains?