Nature riddles: sky, water and weather

I run, but I have no legs.
I have a mouth, but I never speak.
I am born in the hills and I end in the sea.

I walk beside you all day in the sun.
Switch off the light and I am gone.

You can feel me, but you cannot see me.
I dry your clothes and turn the windmill.

I float without wings and I cry without eyes.
When I am dark, carry an umbrella.

I am a bridge of seven colours that nobody can cross.
I appear when the sun meets the rain.

I speak without a mouth.
I only repeat what you shout at the hills.

Feed me and I grow.
Give me a drink and I die.

We come out at night without being called.
We are lost in the day without being stolen.

I stand on one leg all my life.
I give shade to travellers and a home to birds.

I am always moving, but I never leave my bed.
I am salty, and ships ride on my back.

I arrive at night without a sound.
I leave pearls on the grass, and the morning sun takes them away.

You see me first and you hear me a moment later.
I live in storm clouds.