The saying “raining cats and dogs” doesn’t have one proven origin , but several well-known theories and some clear early written uses in 1600s England.

Earliest known uses

  • In 1651, Welsh poet Henry Vaughan wrote about a roof secure against “ dogs and cats rained in shower ,” which is the first known phrase close to “raining cats and dogs.”
  • In 1652, playwright Richard Brome wrote “it shall rain dogs and polecats,” showing similar animal imagery for heavy rain.
  • By 1738, Jonathan Swift used the modern-like form “rain cats and dogs” in his satire A Complete Collection of Genteel and Ingenious Conversation , helping popularize the expression.

So the phrase as we know it seems to take shape in 17th–18th century Britain and spread from there.

Main origin theories

Because no single explanation can be proved, historians and linguists list several competing theories rather than one accepted answer.

1. Norse mythology and storm gods

  • Some writers link it to Norse myths where cats symbolized heavy rain and dogs or wolves were associated with storm winds.
  • Under this theory, “cats and dogs” together would evoke a wild, stormy downpour, later turned into a vivid English idiom.

2. Medieval superstition and street flooding

  • One theory says that in old European cities, heavy storms could wash dead animals like cats and dogs through the streets, making it look as if it had “rained” them.
  • This matches Swift’s own 1710 poem “City Shower,” which describes storms leaving dead animals in the streets, though this still doesn’t prove he invented the phrase from that image.

3. The word catadupe (waterfall)

  • Another theory connects the saying to the obsolete word “catadupe,” used in older English for a cataract or waterfall and related to similar terms in Latin and Greek.
  • Over time, “catadupe” may have been misheard and morphed into “cats and dogs,” preserving the idea of torrential rain even as the original word vanished.

4. Greek phrase cata doxa

  • Some suggest it comes from Greek “cata doxa,” meaning “contrary to belief” or “against expectation.”
  • Under this idea, saying it’s raining “cats and dogs” would mean it is raining in an unbelievable, extraordinary way.

What experts actually say today

  • Major language and archival sources now say the true origin is unknown , even though these colorful theories circulate widely.
  • What is reasonably clear is:
    • The phrase (or very close variants) appears in English writing from the mid‑1600s.
* Jonathan Swift’s 18th‑century works likely helped make “raining cats and dogs” the memorable, lasting version.

So when someone asks “where did the saying ‘raining cats and dogs’ come from?” , the most accurate answer is:

It developed in 17th‑century English, probably from older words and vivid storm imagery, but its exact origin is still a mystery.

TL;DR:
The saying “raining cats and dogs” shows up in English from the 1650s and becomes popular after Jonathan Swift uses it, but whether it came from Norse myths, gross flooded streets, the old word catadupe , or a Greek phrase is still unproven.

Information gathered from public forums or data available on the internet and portrayed here.