Ako do jutra bude samo dva stupnja, smrznut ćemo se bez rukavica.

After ako when you are talking about a future condition, Croatian normally uses the budem form of biti: budem, budeš, bude, budemo, budete, budu.

So:

• Ako do jutra bude... = If by morning it is / will be...

This is the standard pattern. A learner might expect ako će biti, because English uses will sometimes in this kind of idea, but standard Croatian usually does not do that here.

Do takes the genitive case, so jutro becomes jutra.

• nominative: jutro = morning
• genitive: jutra

Do jutra means by morning or until morning, depending on context. In this sentence, by morning is the most natural interpretation.

Because stupanj is a masculine noun.

Croatian uses:

• dva with masculine and neuter nouns
• dvije with feminine nouns

So:

• dva stupnja = two degrees
• dvije minute = two minutes

After 2, 3, and 4, Croatian uses a special counting form.

With many masculine nouns, that form looks like the genitive singular:

• jedan stupanj
• dva stupnja
• tri stupnja
• četiri stupnja

But after 5 and higher, you get the genitive plural:

• pet stupnjeva

So dva stupnja is exactly what you should expect.

This is the future tense of smrznuti se.

In Croatian future I, when the infinitive comes before the auxiliary ću, ćeš, će, ćemo, ćete, će, an infinitive ending in -ti usually drops the final -i:

• smrznuti
  • ćemo → smrznut ćemo

So:

• smrznut ćemo se = we will freeze

Another common structure is to put some other word first, and then the auxiliary comes in second position:

• Mi ćemo se smrznuti
• Sutra ćemo se smrznuti

But standard Croatian does not use smrznuti ćemo se.

Se is part of the verb smrznuti se.

Here the verb means something like:

• to freeze
• to get freezing cold

So you should learn it as a unit: smrznuti se.

If you remove se, the meaning changes or becomes unnatural in this context. In many cases smrznuti without se can be understood more like freeze something or make something become frozen.

Because Croatian often leaves out subject pronouns when the verb form already shows who the subject is.

Here ćemo already tells you it is 1st person plural:

• ćemo = we will

So mi is unnecessary unless you want emphasis or contrast:

• Mi ćemo se smrznuti, a oni neće. = We will freeze, but they won’t.

Because Croatian is using the perfective verb to show a single future result or consequence.

The idea is:

• if the temperature is that low, we’ll end up freezing

That is a natural place for a perfective verb.

An imperfective form such as smrzavati se would suggest an ongoing or repeated process, more like:

• we’ll be getting cold
• we’ll keep freezing

So smrznuti se fits the sentence better.

The preposition bez always takes the genitive case.

The noun is rukavica = glove, and here you have the genitive plural:

• bez rukavica = without gloves

A useful thing to notice is that the genitive plural of some feminine nouns looks the same as the singular base form, so even though rukavica looks unchanged, it is functioning as genitive plural here.

Croatian often leaves out possessive words like my, your, our when they are obvious from context.

So bez rukavica can naturally mean:

• without gloves
• without our gloves

If the speaker wants to be explicit, they can say:

• bez naših rukavica

But in everyday Croatian, that extra possessive is often unnecessary.

Croatian word order is fairly flexible, but it is not completely free. The order here sounds natural because each part is placed where speakers commonly expect it.

For example:

• do jutra appears early, setting the time frame
• samo stands right before what it limits: dva stupnja
• bez rukavica comes at the end as an extra circumstance

You can move parts around for emphasis, but the emphasis changes too. For example:

• Bez rukavica ćemo se smrznuti.

This puts stronger focus on without gloves.

So the sentence is flexible, but the current order is a very normal, neutral way to say it.