Όταν έχει τόση υγρασία, δεν κοιμάμαι καλά, ακόμα κι αν δεν κάνει καύσωνα.

In Greek, weather and environmental conditions are often expressed impersonally. So έχει υγρασία literally means there is humidity, but in natural English we usually say it’s humid.

Greek does not need a dummy subject like English it in sentences such as:

• Έχει κρύο = It’s cold
• Έχει ζέστη = It’s hot
• Έχει υγρασία = It’s humid

So έχει is completely normal here.

Τόση means so much / this much.

It changes form because it agrees with the noun υγρασία, which is:

• feminine
• singular

So you get:

• τόσος for masculine
• τόση for feminine
• τόσο for neuter

Since υγρασία is feminine, Greek uses τόση υγρασία.

Greek often leaves out the article in general expressions like this, especially with weather or conditions.

So:

• έχει υγρασία = it’s humid / there is humidity

This sounds natural and idiomatic. Adding η would usually make it sound more specific, as if you were talking about a particular humidity already known in the context.

It can be understood as either, but in this sentence it is really closer to whenever.

That is because the sentence describes a general repeated situation, not one single event:

• every time there is that much humidity, the speaker does not sleep well

So Όταν έχει τόση υγρασία is essentially Whenever it’s this humid.

Because Greek uses the present tense for habitual or general statements.

Here the speaker is not talking about just one night. They are saying something that is generally true for them:

• when humidity is high, they do not sleep well

So the present tense works like English present in sentences such as:

• When it rains, I stay home
• If I drink coffee late, I don’t sleep well

Both forms exist, but κοιμάμαι is the very common standard intransitive form meaning I sleep or I am sleeping.

A useful distinction for learners is:

• κοιμάμαι = I sleep
• κοιμίζω = I put someone to sleep

You may also hear κοιμάω in some contexts or varieties, but κοιμάμαι καλά is extremely natural here.

Because καλά here is an adverb, not an adjective.

It describes how the person sleeps:

• κοιμάμαι καλά = I sleep well

Compare:

• καλός / καλή / καλό = good, as an adjective
• καλά = well, as an adverb

So Greek is doing the same distinction English does in good versus well.

Ακόμα κι αν means even if.

It introduces something that does not change the main statement. In this sentence, the speaker is saying that high humidity causes poor sleep regardless of whether there is a heatwave.

So the logic is:

• high humidity is enough to cause the problem
• a heatwave is not necessary

This expression is very common in Greek for concession:

• Ακόμα κι αν βρέχει, θα πάω. = Even if it rains, I’ll go.

Κι is simply a shorter form of και.

Before a vowel, Greek very often uses κι instead of και, especially in common fixed expressions. So:

• ακόμα κι αν sounds completely natural and very common.

You could think of it as a smoother spoken form.

This is an idiomatic weather expression.

Greek often uses κάνει with weather nouns or conditions:

• κάνει ζέστη = it’s hot
• κάνει κρύο = it’s cold
• κάνει αέρα = it’s windy
• κάνει καύσωνα = there is a heatwave / it’s scorching hot

So although κάνει literally means does / makes, you should learn κάνει καύσωνα as a set expression.

Because it is the accusative singular form of ο καύσωνας.

The dictionary form is:

• ο καύσωνας = the heatwave

But after κάνει, Greek uses the accusative:

• κάνει καύσωνα

This is similar to other fixed expressions with κάνει.

After αν, Greek normally does not use θα.

Instead, Greek uses the non-past verb form:

• αν κάνει
• αν δεν κάνει

So ακόμα κι αν δεν κάνει καύσωνα is the normal Greek way to say even if there isn’t / even if there won’t be a heatwave, depending on context.

This is a very important Greek pattern:

• Αν έρθει, θα φύγουμε. = If he comes, we’ll leave. not
• Αν θα έρθει... in standard usage

Because each clause is negated separately.

• δεν κοιμάμαι καλά = I don’t sleep well
• αν δεν κάνει καύσωνα = if there isn’t a heatwave

Greek handles this very naturally. The first δεν negates the main clause, and the second δεν negates the subordinate clause.

Yes. Greek word order is more flexible than English word order.

The original sentence is very natural because it gives:

1. the situation
2. the result
3. the extra concessive comment

But Greek could also rearrange parts for emphasis, for example:

• Ακόμα κι αν δεν κάνει καύσωνα, όταν έχει τόση υγρασία, δεν κοιμάμαι καλά.

That version is also possible, but the original sounds smooth and natural in everyday speech.