Η πρόγνωση λέει ότι αύριο θα έχει καύσωνα, γι’ αυτό δεν θέλω να βγω το μεσημέρι.

Greek uses the definite article much more often than English. So η πρόγνωση means the forecast, and that sounds completely natural in Greek.

The noun πρόγνωση is feminine singular, so it takes the feminine singular article η.

Λέει is the 3rd person singular form of λέω, meaning to say.

So Η πρόγνωση λέει... literally means The forecast says...

This is very similar to natural English, where we also say things like the forecast says it will be hot.

Ότι means that and introduces a clause after verbs like say, know, think, etc.

So:

• λέει ότι... = says that...

In English, that is often optional, but in Greek ότι is very common and often helps make the sentence structure clear.

Yes. In Modern Greek, θα is the particle used to form the future.

So:

• έχει = it has / there is
• θα έχει = it will have / there will be

Greek does not form the future the same way English does. Instead of changing the verb ending into a special future form, it normally uses θα + verb.

This is an idiomatic Greek way to talk about weather.

Literally, θα έχει καύσωνα is something like it will have a heatwave, but the natural meaning is:

• there will be a heatwave
• it will be extremely hot

Greek often uses έχει in weather expressions:

• έχει ζέστη = it’s hot
• έχει κρύο = it’s cold
• θα έχει καύσωνα = there will be a heatwave

So even though it may sound unusual if translated word-for-word, it is perfectly normal Greek.

Because καύσωνα is the accusative form.

The dictionary form is:

• ο καύσωνας = the heatwave

But after έχει, the noun appears in the accusative:

• έχει καύσωνα

So:

• nominative: ο καύσωνας
• accusative: τον καύσωνα / καύσωνα

This is a very common pattern in Greek.

Because the sentence is talking about heatwave conditions in a general sense, not about one specific, already-identified heatwave.

So θα έχει καύσωνα is like saying:

• there will be a heatwave
• it will be scorching hot

If you added the article, it would sound more specific. Without the article, it feels more natural here.

Γι’ αυτό means for this reason, because of that, or more naturally that’s why.

So:

• ..., γι’ αυτό δεν θέλω... = ..., that’s why I don’t want...

The spelling γι’ is a shortened form of για before αυτό. The apostrophe shows that a vowel has been dropped in pronunciation/writing.

You may also see για αυτό, but γι’ αυτό is very common in standard writing.

Δεν is the basic negation word for many verb forms in Greek, and it normally goes directly before the verb.

So:

• θέλω = I want
• δεν θέλω = I do not want / I don’t want

That is the normal position of negation here.

This is a very important Greek pattern.

After θέλω, Greek usually uses να + verb:

• θέλω να βγω = I want to go out

Here βγω is the form used for a single, complete action: go out once, step out, leave the house.

By contrast, βγαίνω / να βγαίνω suggests repeated, ongoing, or habitual action.

So:

• θέλω να βγω = I want to go out (one specific outing)
• θέλω να βγαίνω πιο συχνά = I want to go out more often (habit/repetition)

In this sentence, the speaker means one specific action, so να βγω is the natural choice.

Because Greek often leaves out subject pronouns when they are not needed.

The verb ending already shows the subject:

• θέλω = I want

So Greek does not need εγώ unless the speaker wants emphasis or contrast.

For example:

• δεν θέλω = I don’t want
• εγώ δεν θέλω = I don’t want to / as for me, I don’t want to (more emphasis)

Greek often uses the definite article with parts of the day and time expressions.

So:

• το πρωί = in the morning
• το μεσημέρι = at noon / in the midday period
• το βράδυ = in the evening / at night

Here το μεσημέρι means at midday / around noon. The article is a normal part of the expression.