Yes, the phrase ‘It’s raining cats and dogs’ is a hyperbole. A hyperbole is a figure of speech that involves an exaggeration of ideas for the sake of emphasis. In this case, the phrase exaggerates the intensity of the rain by suggesting that it is so heavy that animals are falling from the sky. Obviously, this is not literally happening, but the exaggeration helps to convey just how heavy the rain is.
Hyperboles are commonly used in everyday language to make descriptions more vivid and dramatic. They help to create a strong impression and can make communication more engaging and memorable. So, when someone says ‘It’s raining cats and dogs,’ they are using a hyperbole to emphasize that it is raining very heavily.