“Under the weather” means feeling ill or unwell, usually with a mild or temporary illness.
This guide explains the expression’s meaning, shows how it works in everyday sentences, and clarifies when a more direct phrase may be better.
What does “under the weather” mean?
When someone says they are under the weather, they mean they do not feel well.
The phrase commonly describes a minor illness, such as a cold, headache, or upset stomach, or a general feeling of being poorly.
It does not identify a specific condition or tell you how serious the illness is.
For example, “I’m feeling a little under the weather, so I’m going to rest” tells the listener that the speaker feels unwell without giving medical details.
The expression is informal and familiar, and it can sound gentler or less specific than saying “I’m sick.”
How to use “under the weather” in a sentence
The idiom most often appears after a form of be or feel.
It is usually used as a subject complement: a person is under the weather or feels under the weather.
- “Maya stayed home because she was under the weather.”
- “I’ve felt under the weather since yesterday.”
- “He seemed a bit under the weather during the meeting.”
- “If you’re still under the weather tomorrow, let me know.”
In these examples, the phrase describes how someone feels.
It is not normally used to name an illness.
For instance, “She has under the weather” is incorrect; say “She is under the weather” or “She feels under the weather.”
Is “under the weather” formal or informal?
“Under the weather” is an everyday idiom.
It works in casual conversation, friendly messages, and many ordinary workplace exchanges, such as telling a colleague why you are taking a sick day.
It can be a tactful choice when you do not want to share personal health details.
For a medical appointment, a formal report, or an urgent message, be more precise. “I have a fever,” “I’m experiencing nausea,” or “I’m too ill to work today” communicates more clearly than the idiom.
The phrase may also understate a serious condition, so it should not replace a clear description when the situation calls for one.
“Under the weather” examples in everyday situations
At work
“I’m under the weather today, so I’ll take a sick day and follow up tomorrow.”
This gives a brief explanation while leaving the details private.
If a manager needs specific information about availability, the speaker can add it separately.
Making or changing plans
“I’m sorry to cancel at the last minute, but I’m feeling under the weather.”
Here, the idiom politely explains why someone cannot attend.
It does not imply that the person has a particular illness or is seeking sympathy.
Checking on someone
“You sounded under the weather on the phone.
Are you feeling any better?”
This is a natural way to refer to someone’s apparent discomfort, though it is considerate to let them decide whether to explain more.
Similar expressions and how they differ
Several expressions describe illness or poor health, but they vary in tone and meaning.
- Feeling sick: A direct, common way to say you are ill.
In some contexts, sick can also mean nauseated. - Feeling unwell: A neutral, slightly more formal alternative that still does not specify symptoms.
- Out of sorts: Feeling unlike yourself or mildly unwell; it can refer to mood as well as physical health.
- Not feeling oneself: Feeling unusually tired, low, or unwell, without necessarily being clearly ill.
- Run-down: Tired or weakened, often after stress, poor sleep, or a busy period; it does not always mean having an illness.
Choose “under the weather” when you want a familiar, conversational way to say you feel ill without naming a cause.
Choose a more precise expression when symptoms or severity matter.
Common questions about “under the weather”
Does “under the weather” always mean physically ill?
Usually, yes.
It most often refers to feeling physically unwell, though speakers may use it broadly for a vague, temporary sense of feeling poorly.
It is not a standard way to describe being sad or upset; phrases such as “feeling low” are clearer for emotional states.
Can you say “a little under the weather”?
Yes. “A little under the weather” and “a bit under the weather” are common ways to suggest that someone feels mildly ill.
The modifiers make the statement less absolute, but they do not specify what is wrong.
Is “under the weather” an idiom?
Yes.
It is an idiom because its everyday meaning—feeling unwell—cannot be worked out simply by interpreting the words literally.
In normal use, it is a set expression rather than a comment about actual weather.
What is the plural form of “under the weather”?
The expression does not have a plural form.
It stays the same whether it describes one person or several: “I’m under the weather” and “They’re under the weather.”