“It’s raining cats and dogs” means it’s pouring—but where did this odd phrase come from? The origin isn’t certain, but several colorful theories have been floated.

One links it to Norse mythology, where storm god Odin was associated with dogs and wolves (wind), and witches—often seen flying with black cats—were tied to stormy weather.

Another theory suggests that in medieval Europe, animals like cats and dogs sometimes slept on thatched roofs and were washed off during heavy rain—giving the illusion they were falling from the sky.

Some scholars point to language: the Greek “cata doxa” means “contrary to expectation,” while the old English word “catadupe” referred to a waterfall—possibly inspiring the phrase.

The expression appeared in print as early as the 17th century, including in Richard Brome’s The City Wit (1652), where it “rained dogs and polecats.”