Il fait beau aujourd'hui.

Because il fait beau is a standard French weather expression. French often uses faire for weather conditions:

• il fait beau = the weather is nice / it’s nice out
• il fait chaud = it’s hot
• il fait froid = it’s cold

So even though faire usually means to do or to make, in weather expressions it works more like to be in English.

It does not refer to a person or thing. It is an impersonal subject, like it in English weather sentences:

• It is raining
• It is hot
• It is nice out

In il fait beau, il is just there because French sentences normally need a subject.

Because with weather, French usually prefers faire in many common expressions.

Compare:

• Il fait beau. = The weather is nice.
• Il est beau. = He is handsome / beautiful.
• C’est beau. = It is beautiful.

So if you said il est beau, a French speaker would usually understand he is handsome, not the weather is nice.

In this expression, the form is fixed: il fait beau.

You do not change it to belle. In weather expressions like this, French uses the masculine singular form:

• il fait beau
• il fait chaud
• il fait froid

A useful way to think about it is that this is just the set phrase French uses for nice weather.

Here, beau does not simply mean beautiful in the usual sense. In weather expressions, it means something more like:

• nice
• fine
• pleasant
• good weather

So il fait beau aujourd’hui is more naturally understood as the weather is nice today or it’s nice out today.

Because aujourd’hui is a fixed word with a historical apostrophe in it. For a learner, the important thing is simply to memorize the spelling:

• aujourd’hui = today

It is written as one word with an apostrophe in the middle.

It is flexible. You can put it at the end, at the beginning, or sometimes elsewhere for emphasis.

Common options:

• Il fait beau aujourd’hui.
• Aujourd’hui, il fait beau.

Both are natural. Putting aujourd’hui first can slightly emphasize today.

A simple pronunciation guide is:

eel feh boh oh-zhoor-dwee

A more accurate IPA version is:

/il fɛ bo o.ʒuʁ.dɥi/

A few pronunciation notes:

• fait sounds like feh
• beau sounds like boh
• aujourd’hui has a soft j sound, like the s in measure
• The final il in this sentence is usually very light

A few natural ways are:

• Il fait beau aujourd’hui ? = Is the weather nice today?
• Est-ce qu’il fait beau aujourd’hui ?
• Fait-il beau aujourd’hui ? = more formal

In everyday speech, Il fait beau aujourd’hui ? and Est-ce qu’il fait beau aujourd’hui ? are the most common.

You put ne ... pas around fait:

• Il ne fait pas beau aujourd’hui. = The weather is not nice today.

In informal spoken French, people often drop ne:

• Il fait pas beau aujourd’hui.

But in standard written French, use ne ... pas.

Not if you mean the weather is nice today.

• Il fait beau aujourd’hui = correct for weather
• C’est beau aujourd’hui = more like it’s beautiful today, often referring to how things look in general

So for a normal weather statement, il fait beau is the standard choice.

Yes. These are very common and follow the same pattern:

• Il fait chaud. = It’s hot.
• Il fait froid. = It’s cold.
• Il fait mauvais. = The weather is bad.
• Il fait du vent. = It’s windy.
• Il fait du soleil. = It’s sunny.

Learning il fait ... as a weather pattern will help you sound more natural in French.