Learn Hardcore Croatian: Danas je temperatura visoka.

In Croatian, short forms like je (is) are clitics and prefer the “second position” in the clause. Since Danas is the first element, the clitic je naturally comes right after it: Danas je temperatura visoka. If you start with a different word, the clitic still goes second: Temperatura je danas visoka.

Why is it “visoka” and not “visok” or “visoko”?

Adjectives agree with the noun in gender, number, and case. Temperatura is feminine singular nominative, so the adjective must be feminine singular nominative: visoka. Masculine would be visok, neuter visoko.

Can I say “Danas je visoka temperatura” instead? Does it change the meaning?

Both are correct. Danas je temperatura visoka is the neutral statement (subject first, then predicate). Danas je visoka temperatura moves focus/emphasis to the adjective phrase, sounding a bit more stylistic or contrastive (e.g., “Today, it’s a high temperature” as the noteworthy fact).

Could I just say “Danas je vruće” to mean “It’s hot today”? How is that different?

Yes. Danas je vruće (“It’s hot today”) describes how it feels (the weather/air). Danas je temperatura visoka states a measured property. Other common feel-based options: Danas je toplo (warm), Danas je hladno (cold).

Why not “visoko” here? I’ve seen “-o” on adjectives when there’s no clear subject.

Visoko is neuter or adverbial. You use neuter forms when the subject is an impersonal “it” (e.g., Vruće je danas). Here the subject is explicit and feminine (temperatura), so the adjective must be feminine: visoka.

Which case is “visoka” in, and why isn’t it instrumental or something else?

It’s nominative feminine singular. With the copular verb biti (to be), the subject complement (predicative adjective) is in the nominative and agrees with the subject: temperatura (NOM) je visoka (NOM).

Can I drop “je” and say “Danas temperatura visoka”?

Not in standard Croatian. Headlines or very informal speech may omit it for brevity, but the correct full sentence requires je.

Where else can I put “danas”? Are these all okay?

All of these are fine, with slight shifts in emphasis:

Danas je temperatura visoka.
Temperatura je danas visoka.
Temperatura je visoka danas. (less common, end-focus) Remember the clitic je should stay in second position within its clause.

Do I need an article like “the” before “temperatura”?

No. Croatian has no articles. Context provides definiteness, or you can use demonstratives if needed (e.g., ta temperatura = that temperature).

How do I ask “What’s the temperature today?” naturally?

Common options:

Kolika je danas temperatura? (expects a value; literally “How big is the temperature today?”)
Koja je danas temperatura? (also common)
Koliko je danas stupnjeva? (“How many degrees is it today?”)

How do I compare temperatures, like “Today the temperature is higher than yesterday”?

Use the comparative viša (feminine of “higher”): Danas je temperatura viša nego jučer. With nouns you can also say: Danas je temperatura viša od jučerašnje (temperature). Don’t say “temperatura je više” (više is an adverb); you need the adjective form viša.

What are the opposite and related adjectives?

visoka temperatura = high temperature
niska temperatura = low temperature
Intensifiers: jako/vrlo/izuzetno/prilično visoka temperatura
For how it feels: vruće (hot), toplo (warm), svježe (cool), hladno (cold)

Should I use “topla” with temperature, like “temperatura je topla”?

No. You use topla/topao (warm) with things like water or rooms (voda je topla). With the noun temperatura, use scale adjectives: visoka/niska.

How do I put this in the past or future?

Past: Jučer je temperatura bila visoka.
Future: Sutra će temperatura biti visoka. Notice the clitics: je/će go to second position, and the main verb appears as bila/biti.

Why do forecasts sometimes say “Temperature su visoke” (plural)?

They’re talking about temperatures across regions or times (a set), so they pluralize: Danas su temperature visoke u cijeloj zemlji. For one specific place, use singular: Temperatura je visoka.

Is “jest” possible instead of “je”?

Yes, jest is a full, emphatic or formal form of “is.” You might see it for emphasis or in careful style: Danas jest visoka temperatura, but in everyday speech je is standard.