Comparing thunder to sounds:
* The thunder roared like a lion.
* The thunder boomed like a cannon.
* The thunder crackled like a fire.
* The thunder rumbled like a distant earthquake.
* The thunder crashed like a falling tree.
* The thunder whispered like a gentle breeze (for distant thunder).
Comparing thunder to other phenomena:
* The thunder felt like a giant hand slapping the earth.
* The thunder seemed to shake the very foundations of the house.
* The thunder was like a giant's laughter echoing across the sky.
* The thunder was like a sudden, explosive wave crashing over the world.
Using metaphors to describe thunder:
* Thunder was the voice of the storm.
* The sky was a canvas of lightning and thunder.
* The air crackled with the energy of thunder.
You can also use similes to describe the effect of thunder, like:
* The thunder made my heart pound like a drum.
* The thunder left me feeling as shaken as a leaf in a hurricane.
Ultimately, the best simile for thunder depends on the specific context and the desired effect.