U kolovozu moja baka rijetko dolazi u grad, jer joj je srpanj bio dovoljno vruć.

Because u can take different cases depending on meaning.

• u + accusative usually means movement into somewhere.
• u + locative usually means being in something, including time expressions like in August.

Here, u kolovozu means in August, so kolovoz is in the locative singular.

• nominative: kolovoz
• locative: kolovozu

So this is a normal time expression: u kolovozu = in August.

They are Croatian names for months:

• kolovoz = August
• srpanj = July

In the sentence:

• u kolovozu = in August
• srpanj = July

Notice that month names decline like ordinary nouns, so their endings change depending on case.

Because they play different grammatical roles.

• u kolovozu is a time expression with u, so kolovoz must be in the locative.
• srpanj is the subject of the second clause, so it stays in the nominative.

In jer joj je srpanj bio dovoljno vruć:

• srpanj = the thing being talked about
• therefore nominative is used

So the difference is caused by case, not by the words themselves.

Dolazi is the imperfective form, and that fits well with rijetko (rarely).

• dolaziti = to come / to be coming / to come repeatedly or habitually
• doći = to come, usually seen as a completed event

Since the sentence describes a habit or repeated situation in August, Croatian normally uses the imperfective:

• moja baka rijetko dolazi u grad = my grandmother rarely comes to town

Using dođe here would sound more like a single completed occurrence or a different nuance, and it would not fit as naturally with rijetko.

Because here u expresses movement toward a destination: to town / into town.

With u:

• u + accusative = motion into/to
• u + locative = location in

So:

• dolazi u grad = she comes to town
• je u gradu = she is in town

This is one of the most important Croatian case patterns to learn.

Joj is the dative singular form of the pronoun ona (she).

Basic forms:

• nominative: ona = she
• accusative: nju / je
• dative: njoj / joj = to her / for her

In this sentence, joj means something like for her or to her:

• jer joj je srpanj bio dovoljno vruć

A natural English interpretation is:

• because July was hot enough for her
• or because July was hot enough for her already

Croatian often uses the dative pronoun where English uses for.

Because Croatian very often uses the dative pronoun to express the person affected by something.

So:

• joj je ... dovoljno vruć = it is / was hot enough for her
• za nju is also possible in some contexts, but it is not the most natural choice here

The dative version sounds idiomatic and elegant. It expresses that from her point of view, July was already sufficiently hot.

Dovoljno means enough and vruć means hot.

Together:

• dovoljno vruć = hot enough

Croatian often places dovoljno before the adjective:

• dovoljno velik = big enough
• dovoljno brz = fast enough
• dovoljno vruć = hot enough

Here vruć agrees with srpanj, which is masculine singular, so the masculine singular form vruć is used.

Actually, the sentence does contain je:

• jer joj je srpanj bio dovoljno vruć

Croatian past tense is formed with:

• the present of biti (sam, si, je, smo...)
• plus the past participle

So:

• je bio = was

The reason it may look unusual is that Croatian clitic words such as je and joj often appear in second position in the clause.

That is why you get:

• jer joj je srpanj bio dovoljno vruć

rather than a more English-like order.

Because joj and je are clitics, and Croatian clitics usually go near the beginning of the clause, typically in second position.

So after jer, the clitics come early:

• jer joj je srpanj bio dovoljno vruć

This is very normal Croatian word order.

A learner-friendly way to think about it:

• jer starts the clause
• then the short unstressed words joj je come as early as possible
• then the full noun srpanj

Rijetko is an adverb meaning rarely.

It modifies dolazi:

• moja baka rijetko dolazi u grad = my grandmother rarely comes to town

Croatian adverbs often stand before the verb, just as in this sentence:

• često dolazi = she often comes
• rijetko dolazi = she rarely comes

Yes, in principle the Croatian present tense can sometimes correspond to either simple present or present continuous in English, depending on context.

But here, because of rijetko and the general meaning of the sentence, the natural interpretation is habitual:

• rijetko dolazi = rarely comes

It does not sound like is coming in this context.

Because jer means because and introduces a subordinate clause.

In standard Croatian writing, a comma is normally used before jer:

• ..., jer ...

So the sentence is correctly punctuated:

• U kolovozu moja baka rijetko dolazi u grad, jer joj je srpanj bio dovoljno vruć.

Both are possible, but moja baka means my grandmother explicitly.

Croatian often uses possessive adjectives such as:

• moj / moja / moje = my
• tvoj / tvoja / tvoje = your

Since baka is feminine singular, the form is:

• moja baka

The possessive adjective must agree with the noun in gender, number, and case.

Yes. Grad can mean either city or town, depending on context.

So:

• u grad can be translated as to the city or to town

In many everyday sentences, English to town is the most natural translation, even though the Croatian word is simply grad.

Yes. The second clause suggests a kind of personal threshold:

• July was hot enough for her

This implies that after July’s heat, she does not feel much need or desire to come into town in August. The dative joj makes it sound personal and subjective: as far as she is concerned, July was already plenty hot.

So the sentence is not only factual; it also carries a slight nuance of that was enough for her.