If you’re learning English, under the weather is a useful idiom for everyday conversations. It usually means feeling slightly sick or unwell.
This guide explains the phrase in clear American English. You’ll learn its meaning, grammar patterns, examples, synonyms, common mistakes, formality, and possible origin.
Quick Answer
Under the weather means feeling sick, unwell, or not completely well. It is an informal idiom, as in: “I’m feeling under the weather today.”
TL;DR
• Under the weather usually means feeling slightly ill.
• It is an informal English idiom.
• Feeling under the weather is a common construction.
• Always use the in the fixed expression.
• Sick, ill, and unwell are alternatives.
• The phrase probably has nautical roots.
What Does “Under the Weather” Mean?
Under the weather means that someone does not feel well. Major English dictionaries describe it as an informal expression for being somewhat ill.
It normally gives a general idea rather than a specific diagnosis. You can use it when you do not want to explain exactly what is wrong.
• “I’m under the weather today.”
• “She feels under the weather.”
• “He has been under the weather all week.”
• “I’m a little under the weather.”
• “Are you feeling under the weather?”
• “They were under the weather yesterday.”
• “My sister seems under the weather.”
• “I felt under the weather after a long week.”
Is “Under the Weather” an Idiom?
Yes. Under the weather is an idiom because its meaning is not literal.
The individual words suggest a physical location, but the complete expression describes someone’s condition.
• Idiom: under the weather
• Meaning: feeling unwell
• Style: informal
• Use: everyday English
• Literal meaning: physically beneath the weather
• Intended meaning: not feeling well
• Common form: “I’m under the weather.”
• Another common form: “I feel under the weather.”
How Do You Use “Under the Weather”?
Use under the weather after a form of be or with feel. The phrase can work with different subjects and verb tenses.
The wording under the weather stays unchanged. Only the surrounding verb changes.
• “I am under the weather.”
• “She is under the weather.”
• “They are under the weather.”
• “He felt under the weather.”
• “We were under the weather.”
• “I feel under the weather.”
• “She has been under the weather.”
• “Are you feeling under the weather?”
“Under the Weather” Examples
The phrase is especially natural in casual conversations. It can explain why someone misses work, school, a meeting, or a social event.
• “I’m feeling a little under the weather today.”
• “I can’t come tonight because I’m under the weather.”
• “She stayed home because she felt under the weather.”
• “You look a bit under the weather.”
• “He has been under the weather since Monday.”
• “I was under the weather yesterday, but I feel better now.”
• “My friend is feeling under the weather.”
• “Are you feeling under the weather?”
• “She called her manager because she was under the weather.”
• “I’m a little under the weather, so I’ll rest tonight.”
What Does “Feeling Under the Weather” Mean?
Feeling under the weather means feeling sick or generally unwell. The word feeling emphasizes the person’s current physical state.
This form is very natural in everyday English. It can sound softer than directly saying, “I’m sick.”
Is “Under the Weather” Formal or Informal?
Under the weather is generally informal. It is suitable for conversations, texts, casual messages, and many ordinary workplace situations.
For formal documents, academic writing, or precise medical communication, use clearer wording.
• Casual: “I’m under the weather today.”
• Friendly: “I’ve been feeling under the weather.”
• Workplace: “I’m feeling under the weather and need to rest.”
• Neutral: “I’m not feeling well.”
• More formal: “I’m feeling unwell.”
• Medical: Give the specific information needed.
• Academic: Prefer direct, literal wording.
• Conversation: The idiom sounds natural.
“Under the Weather” in American English
Under the weather is established in American English. Cambridge’s American Dictionary defines it as meaning that someone is not completely well.
The phrase is not limited to one particular illness. Speakers can use it when they simply feel less well than usual.
• “I’m under the weather today.”
• “She’s been a little under the weather.”
• “He looked under the weather.”
• “I’m feeling better now.”
• “She called in because she was under the weather.”
• “Are you still feeling under the weather?”
• “I’ve been under the weather lately.”
• “He seems a little under the weather.”
What Are Synonyms for “Under the Weather”?
Several expressions have similar meanings, but their tone can differ. Cambridge lists sick, ill, unwell, poorly, ailing, and other related terms.
The best synonym depends on whether you want to sound casual, neutral, direct, or more formal.
• Sick: common and direct.
• Ill: neutral and slightly more formal.
• Unwell: polite and neutral.
• Not feeling well: clear and natural.
• Feeling run-down: emphasizes low energy.
• Out of sorts: suggests feeling generally off.
• Below par: suggests being below your normal condition.
• Ailing: more formal and often stronger.
“Under the Weather” vs. “Sick”
Both expressions can mean that someone is not feeling well. The main difference is tone and directness.
Sick gives the information directly. Under the weather is more conversational and less specific.
• “I’m sick.” — Direct.
• “I’m under the weather.” — Softer.
• “She called in sick.” — Common workplace wording.
• “She said she was under the weather.” — Less specific.
• “He is sick today.” — Direct statement.
• “He is feeling under the weather.” — Conversational.
• Use sick when directness matters.
• Use under the weather when a softer expression fits.
“Under the Weather” vs. “Unwell”
Unwell and under the weather are close in meaning. However, unwell is more neutral and can fit formal communication better.
The idiom sounds more conversational and less precise.
• “I’m feeling unwell.” — Neutral.
• “I’m feeling under the weather.” — Informal.
• “She became unwell.” — Neutral.
• “She felt under the weather.” — Conversational.
• “Please stay home if you are unwell.” — Neutral.
• “I’m a little under the weather today.” — Casual.
• Use unwell in formal situations.
• Use under the weather in everyday conversation.
Common Mistakes With “Under the Weather”
The expression has fixed wording. The most common learner mistake is removing the.
The phrase should also be treated as an idiom rather than a literal description.
• Incorrect: “I’m under weather.”
• Correct: “I’m under the weather.”
• Incorrect: “She feels under weather.”
• Correct: “She feels under the weather.”
• Incorrect: “I’m under a weather.”
• Correct: “I’m under the weather.”
• Better: “I’m feeling under the weather.”
• Better formal option: “I’m feeling unwell.”
• Avoid treating the phrase as a medical diagnosis.
• Remember that the belongs to the expression.
Useful “Under the Weather” Sentence Patterns
You can learn the expression quickly by remembering a few complete patterns. These patterns can then be adapted to different subjects and tenses.
• I’m under the weather.
• I feel under the weather.
• She’s under the weather.
• He feels under the weather.
• They were under the weather.
• I was feeling under the weather.
• She has been under the weather.
• Are you feeling under the weather?
• Why are you under the weather today?
• I’m a little under the weather today.
Where Did “Under the Weather” Come From?
The expression is widely associated with nautical language. One traditional explanation connects the phrase with sailors seeking shelter from difficult weather.
However, the exact history is not completely settled. Historical sources point to related nautical expressions, while the modern idiom developed over time.
So, it is safer to say the phrase is generally believed to have nautical roots. A specific origin story should not be treated as proven fact.
Can “Under the Weather” Mean Something Else?
Some dictionaries record a second informal meaning connected with intoxication. Collins includes this secondary sense in its American English entry.
For English learners, however, the main meaning to remember is feeling sick or unwell. Context usually makes the intended meaning clear.
• Main meaning: feeling unwell.
• Secondary dictionary meaning: intoxicated.
• The secondary sense is informal.
• Health-related context usually signals the main meaning.
• “I’m under the weather with a cold” clearly refers to illness.
• “I’m feeling under the weather today” normally refers to feeling unwell.
• Do not assume the secondary meaning without context.
• Learn the illness meaning first.
When Should You Use “Under the Weather”?
Use the expression when you want to say you are not feeling well without giving detailed information.
It is especially useful in casual conversations. For formal situations, choose a more direct expression when precision matters.
• Use it with friends.
• Use it with family.
• Use it in casual texts.
• Use it when declining a social invitation.
• Use it in ordinary workplace communication.
• Use unwell for a neutral tone.
• Use not feeling well for maximum clarity.
• Use specific wording when exact information matters.
Quick Practice: Choose the Correct Sentence
Check whether each sentence uses the fixed phrase correctly. The answers reinforce the most common grammar patterns.
• A: “I’m under weather.”
• B: “I’m under the weather.”
• Answer: B
• A: “She feels under the weather.”
• B: “She feels under weather.”
• Answer: A
• A: “He was under the weather yesterday.”
• B: “He were under the weather yesterday.”
• Answer: A
• A: “I feel under the weather.”
• B: “I feel beneath weather.”
• Answer: A
• A: “Are you feeling under the weather?”
• B: “Are you feeling under weather?”
• Answer: A
• A: “She has been under the weather.”
• B: “She have been under the weather.”
• Answer: A
• A: “I’m feeling under the weather.”
• B: “I’m feeling under weather.”
• Answer: A
• A: “I’m feeling unwell.”
• B: “I’m feeling weather.”
• Answer: A
FAQs
What is the simple meaning of “under the weather”?
Under the weather means feeling slightly sick or unwell. It is an informal expression used in everyday English.
Is “under the weather” grammatically correct?
Yes. It is a standard English idiom recognized by major dictionaries. The fixed form includes the word the.
Can I say “I’m feeling under the weather”?
Yes. “I’m feeling under the weather” is a natural sentence. You can also say “I feel under the weather” or “I’m under the weather.”
Is “under the weather” formal?
No, it is generally informal. For formal writing, unwell or not feeling well may be a better choice.
What is another way to say “under the weather”?
You can say sick, ill, unwell, not feeling well, or feeling run-down. Choose the alternative based on the exact meaning and tone you need.
Is “under the weather” American English?
Yes. The phrase is used in American English as well as British English. Major dictionaries document the expression in both varieties.
Where does “under the weather” come from?
The phrase is commonly linked to nautical language. The exact development is uncertain, so the nautical explanation is best described as a commonly accepted theory rather than a proven single origin.
Conclusion
Under the weather means feeling slightly sick or unwell, and it is a common informal expression in American English. It is useful when you want to describe feeling unwell without giving many details.
Remember the fixed form under the weather, practice the sentence patterns, and compare it with sick and unwell. For your next step, try using the phrase in three original sentences about everyday situations.