It is raining cats and dogs simply means the rain is very heavy. The image is funny on purpose: the sky is not really dropping animals, but the downpour feels as dramatic as that.
The phrase is old and a little old-fashioned. It appeared in English writing in the 1700s and is still used today, often with a smile. Weather small talk is still its natural home.
This page explains the meaning, the grammar, the register and the older phrases you can use instead. The drill at the end has 10 questions with explanations for every answer.
What it means
In one sentence: The idiom raining cats and dogs means it is raining very heavily, in a sudden and dramatic way.
What the idiom means in everyday English
- It describes heavy rain, the kind that floods the road and soaks you in seconds.
- The phrase is used almost only about rain, and almost always with it: "It is raining cats and dogs."
- It is an exaggeration, so it fits a dramatic downpour better than a light shower.
- Weather small talk often uses it: cancelled plans, wet clothes and umbrellas.
How the idiom behaves in a sentence
- The normal pattern is it + be + raining + cats and dogs: "It is raining cats and dogs outside."
- Tense changes go on the verb rain: it rained cats and dogs all night, it was raining cats and dogs when we arrived.
- You can say it started raining / began raining cats and dogs for the moment the heavy rain began.
- Do not add a or the before the animals: raining cats and dogs, never raining the cats and dogs.
When the idiom does not fit
- Do not use it for snow, wind or sunshine. The idiom is fixed to heavy rain.
- It is rarely used in formal writing. A weather report says "heavy rain" or "torrential rain".
- Do not use it for a light drizzle; that is the opposite kind of rain.
- Some speakers find the phrase old-fashioned. Pouring, bucketing down or chucking it down sound more modern in British English.
Where it comes from
A close form appears in the 1600s, and Jonathan Swift wrote "it rains cats and dogs" in his 1738 book Polite Conversation. The reason cats and dogs were chosen is not documented; the popular stories about flooded streets and dead animals are guesses, so treat them with care.
Use it or not
Register: Informal, and slightly dated. Raining cats and dogs is fine in conversation, in messages and in children’s books, and it often sounds humorous. Modern weather talk in Britain prefers "it is pouring" or "it is bucketing down". In a news report or a formal email, write "heavy rain" instead. It is never rude.
Examples
- Take your umbrella; it is raining cats and dogs out there.The phrase explains why an umbrella is needed.
- We wanted to walk to the station, but it was raining cats and dogs.The past continuous form describes the weather during the walk.
- It rained cats and dogs all night and the road was flooded by morning.The past simple with all night shows a finished period.
- The match was cancelled because it was raining cats and dogs.A common reason for cancelling an outdoor plan.
- It started raining cats and dogs just as we left the house.Started raining marks the exact moment the downpour began.
- You cannot go out in this. It is raining cats and dogs!The idiom often appears as an exclamation.
- The forecast says it will rain cats and dogs tomorrow.The phrase can follow will for a prediction.
Similar idioms
it is pouring
it is raining very hard, the modern everyday phrase.
it is bucketing down
it is raining heavily, common in British English.
it is chucking it down
it is raining hard, very informal British English.
torrential rain
very heavy rain, the formal phrase for reports and news.
a downpour
a sudden, heavy fall of rain.
Practice drill
Answer all 10 questions. Each answer is marked at once, and the meaning is explained under the question.
Take an umbrella. It is ___ outside.
Show answer and explanation
Answer: A. raining cats and dogs Raining cats and dogs means heavy rain, which is exactly why an umbrella is needed.
Which sentence uses raining cats and dogs correctly?
Show answer and explanation
Answer: B. It was raining cats and dogs, so the streets were empty. The idiom describes heavy rain, so empty streets in the downpour make sense; sunshine and snow do not fit the idiom.
What does it is raining cats and dogs mean?
Show answer and explanation
Answer: C. It is raining very heavily. Raining cats and dogs is an exaggerated way to say the rain is very heavy.
The picnic was cancelled because ___.
Show answer and explanation
Answer: D. it was raining cats and dogs Heavy rain is a reason to cancel a picnic, and raining cats and dogs means heavy rain.
Which weather does the idiom describe?
Show answer and explanation
Answer: A. heavy rain Raining cats and dogs is fixed to heavy rain and is not used for other kinds of weather.
Choose the sentence with the same meaning: "It was raining cats and dogs."
Show answer and explanation
Answer: B. It was pouring with rain. Raining cats and dogs means raining heavily, so "it was pouring with rain" has the same meaning.
Which is correct?
Show answer and explanation
Answer: C. It rained cats and dogs all night. The fixed idiom has no article and describes rain: it rained cats and dogs all night.
You are soaked after walking home. What is a natural thing to say?
Show answer and explanation
Answer: D. It is raining cats and dogs out there. Raining cats and dogs describes the heavy rain that soaked you; the other options mix unrelated idioms.
Which sentence does NOT use the idiom correctly?
Show answer and explanation
Answer: A. It is raining cats and dogs, a perfect day for the beach. Heavy rain is not a perfect day for the beach, so the last sentence uses the idiom in a situation that does not fit.
A friend asks about the weather in London. It has been pouring all day. What can you reply?
Show answer and explanation
Answer: B. It has been raining cats and dogs. Raining cats and dogs means pouring rain, so it matches the weather the friend asked about.
Questions learners ask
Is raining cats and dogs formal or informal?
It is informal and slightly old-fashioned. Use it in conversation or in light writing. In a formal text, choose "heavy rain" or "torrential rain".
Why do we say raining cats and dogs?
The phrase is recorded in the 1700s, and Jonathan Swift used it in 1738. The reason for the animals is not documented. Popular stories about cats and dogs falling from roofs or from ships are guesses, not proven history.
Can I use the idiom for any heavy weather?
No. The idiom belongs to rain only. For heavy snow, say "it is snowing heavily"; for strong wind, say "the wind is howling". Using the phrase for anything other than rain sounds wrong.
More idioms
Call it a day
To call it a day is to stop working on something for now, because you have done enough or because the work can wait.
Hit the sack
To hit the sack is to go to bed, usually because you are tired and ready to sleep.
Ring a bell
If a name, a face or a story rings a bell, it sounds familiar, even if you cannot remember where you know it from.
Browse all the idiom pages or take the free A1 to C2 level test to find your starting point.