Το καλοκαίρι ψάχνω πάντα ίσκιο όταν έχει πολύ ήλιο.

In Greek, time expressions often use the article + noun by itself to mean in/during a season, month, or part of the day.

So το καλοκαίρι means in summer or during the summer.

This is very common:

• τον χειμώνα = in winter
• την άνοιξη = in spring
• το βράδυ = in the evening

You can sometimes use a preposition in other contexts, but here το καλοκαίρι is the normal natural way to express a general time setting.

In this sentence, it most naturally means in summer / during the summer generally, not necessarily this summer.

Greek often uses the definite article in general statements:

• Το καλοκαίρι ψάχνω πάντα ίσκιο = In summer, I always look for shade.

If you specifically wanted this summer, Greek would usually make that clearer from context or by adding a word such as φέτος:

• Φέτος το καλοκαίρι... = This summer...

Greek often leaves out subject pronouns because the verb ending already shows who the subject is.

Here, ψάχνω means I look for / I am looking for, so εγώ is unnecessary.

• ψάχνω = I look for
• ψάχνεις = you look for
• ψάχνει = he/she/it looks for

You can include εγώ for emphasis or contrast, but normally Greek does not need it.

In Greek, ψάχνω can take a direct object without any preposition:

• ψάχνω ίσκιο = I’m looking for shade

You may also hear ψάχνω για..., which is also possible in many contexts, but ψάχνω + direct object is very common and often more straightforward.

So this sentence is completely natural.
A learner should get used to the fact that Greek ψάχνω often works differently from English look for.

Ίσκιος / ίσκιο means shade or shadow, and in this sentence it means shade.

A very common alternative is σκιά. Both can refer to shade, but there can be slight differences in tone, region, or style.

In everyday use:

• ψάχνω ίσκιο = I look for shade
• ψάχνω σκιά = I look for shade

Both are understandable, but ίσκιο has a very natural, everyday feel in this kind of sentence.

Also note the form:

• dictionary form: ο ίσκιος
• here: ίσκιο, because it is the direct object

Yes, Greek word order is flexible, and adverbs like πάντα can move around.

Here:

• Το καλοκαίρι ψάχνω πάντα ίσκιο = In summer I always look for shade

This is natural and idiomatic. You could also hear:

• Το καλοκαίρι πάντα ψάχνω ίσκιο
• Πάντα ψάχνω ίσκιο το καλοκαίρι

The meaning stays basically the same, but the emphasis changes a little.
The original sentence sounds very natural and balanced.

Yes, literally that is how Greek expresses it.

Έχει ήλιο is a very common Greek expression meaning:

• it’s sunny
• there is sunshine
• the sun is strong / out

So:

• όταν έχει ήλιο = when it’s sunny
• όταν έχει πολύ ήλιο = when it’s very sunny / when there is a lot of sun

This is one of those expressions that sounds more natural in Greek than a word-for-word English translation.

Here έχει is used impersonally, like English it’s in weather expressions.

Greek often uses έχει in expressions about weather or conditions:

• έχει ήλιο = it’s sunny
• έχει ζέστη = it’s hot
• έχει κρύο = it’s cold

There is no explicit subject word. It works a bit like an impersonal it in English.

Because πολύ here means a lot of, and it stays in the form πολύ before the noun.

In this expression:

• πολύ ήλιο = a lot of sun

Compare:

• πολύ νερό = a lot of water
• πολύ φως = a lot of light

This is different from πολύς, πολλή, πολύ, which changes form when used as an adjective meaning much/many with countable nouns in full agreement patterns.
But with mass nouns and common expressions like πολύ ήλιο, πολύ is exactly what you expect.

Because ήλιο is the direct object of έχει in the expression έχει ήλιο.

The base noun is:

• ο ήλιος = the sun

But after έχει, Greek uses the accusative:

• έχει ήλιο = it’s sunny / there is sun
• έχει πολύ ήλιο = there is a lot of sun

So ήλιο is not the subject here. It is the object inside a fixed, common expression.

It describes a habit or general repeated action.

• ψάχνω πάντα ίσκιο = I always look for shade

Greek present tense, like English present tense, can express habitual actions:

• Το καλοκαίρι πίνω πολύ νερό = In summer I drink a lot of water
• Όταν έχει ζέστη, μένω μέσα = When it’s hot, I stay inside

So the sentence means this is something the speaker generally does.

Yes. Greek allows quite a bit of flexibility in word order, especially with time phrases and subordinate clauses.

For example:

• Όταν έχει πολύ ήλιο, το καλοκαίρι ψάχνω πάντα ίσκιο.
• Το καλοκαίρι, όταν έχει πολύ ήλιο, ψάχνω πάντα ίσκιο.

These all mean basically the same thing. The differences are mainly about rhythm, focus, and style.

The original sentence is natural because it first sets the general time frame το καλοκαίρι, then gives the main action ψάχνω πάντα ίσκιο, and finally adds the condition όταν έχει πολύ ήλιο.

Όταν means when, not if.

So:

• όταν έχει πολύ ήλιο = when it’s very sunny

It introduces a time clause: the speaker looks for shade at those times.

If you wanted if, Greek would normally use αν:

• αν έχει πολύ ήλιο... = if it’s very sunny...

In this sentence, όταν suggests something expected or repeated, which fits the habitual meaning of the whole sentence.