This is an English idiom. An idiom is not easily translatable to another language. This particular one means that it is raining very hard.

It means it is raining heavily with strong wind or storm

Hi Beto. It means that it is raining unusually hard. It comes from the Greek expression cata doxa which means"contrary to experience or belief". If it is raining cats and dogs, it is raining unusually hard.

"It's raining cats and dogs" means that it is raining heavily. <3

It means that’s it’s pouring. The rain is pouring.