आज बारिश हो रही है।

In Hindi, weather expressions often do not use a dummy subject like English it.

In English, we say It is raining, but the it does not refer to anything specific. Hindi usually just says:

• बारिश हो रही है = It is raining / Rain is happening

So Hindi expresses the event directly, without needing a subject like English it.

A word-by-word breakdown is:

• आज = today
• बारिश = rain / rainfall
• हो = from the verb होना, to be / to happen
• रही = the continuous/progressive part, agreeing with a feminine singular noun
• है = is

So literally, it is something like:

• Today rain is happening

Natural English:

• It is raining today
• Today it is raining

Hindi often expresses weather events like rain as something that is happening.

So:

• बारिश हो रही है literally means rain is happening

This is a very common and natural way to say it is raining.

The structure is:

• होना = to happen / to occur / to be
• रहा / रही / रहे = progressive marker, like English -ing
• है = present tense is

Together, हो रही है gives the meaning is happening.

Because बारिश is a feminine singular noun.

In Hindi, the progressive participle agrees with the noun or subject in many intransitive sentences like this one.

So:

• masculine singular → रहा
• feminine singular → रही
• plural → रहे

Since बारिश is feminine singular, we say:

• बारिश हो रही है

not

• बारिश हो रहा है

Because बारिश is singular.

• है = is
• हैं = are

Since बारिश is one singular noun, the sentence uses है:

• बारिश हो रही है = It is raining

If the subject were plural, you would normally use हैं.

No. आज just adds the meaning today.

Without it:

• बारिश हो रही है। = It is raining.

With it:

• आज बारिश ho रही है। = It is raining today.

So आज is optional if the context already makes the time clear.

Yes, Hindi word order is somewhat flexible, especially for time words like आज.

These are all possible, though some may sound more natural depending on context:

• आज बारिश हो रही है।
• बारिश आज हो रही है।
• बारिश हो रही है आज।

The most neutral and common version is:

• आज बारिश हो रही है।

Hindi often puts time expressions near the beginning.

It is present continuous (also called the progressive), like English is raining.

The pattern is:

• verb stem + रहा / रही / रहे
  • है / हैं

Here:

• हो रही है = is happening

So the sentence describes an action or event in progress right now / around now.

Usually, आज बारिश है is not the normal way to say it is raining.

• बारिश हो रही है means rain is actively falling / happening.
• बारिश है can sound incomplete or more like there is rain in a broad sense, not necessarily that it is raining right now.

If you want the natural meaning it is raining, use:

• बारिश हो रही है

Yes. Another common expression is:

• बारिश पड़ रही है।

This also means it is raining.

Difference in feel:

• बारिश हो रही है = very common, neutral, natural
• बारिश पड़ रही है = also common, often feels a bit more specifically like rain is falling

Both are widely understood and natural.

बारिश is pronounced roughly like baa-rish.

A few helpful notes:

• बा has a long aa sound, like father
• रि is a short ri
• श is sh, as in shoe

So: baa-rish

Also, do not pronounce it like English bear-ish. The first vowel is longer and more open.

It is neutral and completely natural in everyday Hindi.

You can use it in:

• normal conversation
• writing
• simple descriptions
• language learning examples

It is neither especially formal nor especially casual. It is just a standard, correct sentence.