الموسم ده فيه رطوبة كتير.

A natural pronunciation is:

el-mōsem da fīh raṭūba كتير
More smoothly: el-mōsem da fīh raṭūba كتīr

A rough English-friendly version: el-MOH-sem da feeh ra-TOO-ba k-teer

A few notes:

• الـ is usually pronounced el- in Egyptian Arabic.
• ده sounds like da.
• فيه sounds like fīh or feeh.
• رطوبة is raṭūba; the ṭ is a heavier t sound than English t.
• كتير is ktīr / kteer.

الموسم literally means the season.

In this sentence, it can refer to:

• a literal season of the year, like summer or winter
• more generally, this time of year

So in everyday English, the whole sentence may feel like:

• This season is very humid
• There’s a lot of humidity this time of year

In Egyptian Arabic, demonstratives like ده (this) usually come after the noun, not before it.

So:

• الموسم ده = this season
• literally: the season this

This is very normal in Egyptian Arabic.

More examples:

• البيت ده = this house
• الجو ده = this weather / this atmosphere
• الكتاب ده = this book

So the word order is different from English, but it is the standard Egyptian pattern.

Here, فيه means there is / there are.

So:

• فيه رطوبة = there is humidity
• فيه ناس = there are people

Literally, فيه can also mean in it / in him, depending on context, but in sentences like this it functions as an existential expression: there is / there are.

So the structure is:

• الموسم ده = this season
• فيه = there is
• رطوبة كتير = a lot of humidity

Because فيه is what makes the sentence sound like there is / there’s.

Without فيه, the sentence would sound incomplete or unnatural for this meaning.

Egyptian Arabic often uses فيه to introduce the existence of something:

• فيه مشكلة = there is a problem
• فيه وقت = there is time
• فيه رطوبة = there is humidity

So الموسم ده فيه رطوبة كتير is literally structured like: This season, there is a lot of humidity.

رطوبة means humidity or moisture, and here it is a noun.

That is important because the sentence is not built like:

• the season is humid

It is built more like:

• there is a lot of humidity

So instead of using an adjective like humid, Egyptian Arabic here uses the noun رطوبة.

Here كتير means a lot, much, or very much.

So:

• رطوبة كتير = a lot of humidity

كتير is a very common Egyptian word and can be used in several ways:

• بحبك كتير = I love you a lot
• فيه ناس كتير = there are many people
• مطر كتير = a lot of rain

So in this sentence, it is intensifying رطوبة: there is a lot of it.

Good question. In Egyptian Arabic, كتير often works like an adverb or quantity word meaning a lot, and in that use it is very commonly left as كتير.

So:

• رطوبة كتير
• مياه كتير
• فلوس كتير

are all very normal.

You may also hear forms that look more like adjective agreement in some contexts, but in this sentence كتير is the expected everyday choice.

The sentence is:

الموسم ده | فيه | رطوبة كتير

You can think of it as:

1. Topic: الموسم ده = this season
2. Existence: فيه = there is
3. What exists: رطوبة كتير = a lot of humidity

So the feeling is:

As for this season, there is a lot of humidity.

This kind of topic-first structure is very common in Arabic.

Not exactly in the same way as English.

Arabic often leaves out the present-tense verb to be in simple sentences. But here, the sentence is not mainly using a hidden is structure. Instead, it uses the existential فيه = there is.

So it is closer to:

• This season, there is a lot of humidity

rather than:

• This season is a lot of humidity

If you wanted a sentence more like The weather is humid, you would usually phrase it differently.

Yes. A few common alternatives are:

• الجو فيه رطوبة كتير
  The weather is very humid / There’s a lot of humidity in the air

• الجو رطب
  The weather is humid

• الفترة دي فيها رطوبة كتير
  This period has a lot of humidity / It’s very humid these days

Your original sentence is very natural, especially if you mean this season / this time of year.

Both can refer to a stretch of time, but they feel a little different:

• الموسم ده = this season / this time of year
• الفترة دي = this period / these days / lately

So:

• الموسم ده فيه رطوبة كتير sounds more seasonal.
• الفترة دي فيها رطوبة كتير sounds more like talking about the current period in general.

Also notice:

• masculine noun + ده
• feminine noun + دي

So:

• الموسم ده
• الفترة دي

Yes. In careful transliteration it is often written fīh. In looser English spelling, learners often write:

• feeh
• fih
• fiih

They all point to roughly the same Egyptian pronunciation.

Just remember that in this sentence it is a very common everyday word meaning there is.

A natural Egyptian Arabic version would be:

الموسم ده مفيش فيه رطوبة كتير

or more simply:

الموسم ده مفيش رطوبة كتير

Here:

• مفيش = there isn’t / there aren’t

Compare:

• فيه رطوبة كتير = there’s a lot of humidity
• مفيش رطوبة كتير = there isn’t much humidity

This is a very useful pattern:

• فيه = there is
• مفيش = there isn’t