Vejret er vildt.

Because vejret is the definite singular form of vejr.

• et vejr = a weather / a type of weather (less common by itself in everyday use)
• vejret = the weather

When Danish talks about the weather in general or the current weather, it usually uses the definite form, just like English says the weather.

So:

• Vejret er vildt. = The weather is wild.

The base form is vejr, which is a neuter noun.

Its forms are:

• et vejr = indefinite singular
• vejret = definite singular

This matters because the adjective later in the sentence has to match the noun grammatically.

Because vejr is a neuter noun, and many Danish adjectives take -t in the neuter singular.

Compare:

• en vild dag = a wild day
• et vildt vejr = a wild weather / wild weather
• Vejret er vildt. = The weather is wild.

Even though vildt comes after er, it still agrees with vejret. This is called a predicate adjective.

Here it is an adjective, because it describes vejret.

In Danish, the neuter form of an adjective often looks the same as the adverb form, so learners can get confused.

In this sentence:

• vejret = the thing being described
• er = is
• vildt = wild

So vildt is describing the noun, not modifying the verb.

Yes, in this sentence it is very similar:

• Vejret = subject
• er = verb
• vildt = subject complement / predicate adjective

So it follows the pattern:

Subject + verb + adjective

That said, Danish has V2 word order, so if something else comes first, the verb still stays in second position:

• I dag er vejret vildt. = Today the weather is wild.

Yes, it can sound very natural, especially in spoken or informal Danish.

It often suggests that the weather is:

• intense
• crazy
• dramatic
• extreme
• all over the place

Depending on context, a Dane might also choose more specific words such as:

• blæsende = windy
• stormfuldt = stormy
• voldsomt = violent/intense
• ekstremt = extreme

So vildt is natural, but it is a bit broader and more expressive.

Yes. In real usage, vildt can carry a range of tones depending on context and voice.

About weather, it might mean:

• wild
• crazy
• intense
• extreme
• pretty dramatic

So even if the basic meaning has already been shown to you, it is useful to know that the feeling of the word can be stronger or more colloquial than a plain dictionary translation.

A careful learner-friendly approximation is:

• vejret: starts roughly like vy or vai, with a weak ending
• er: a short, reduced air/er sound
• vildt: roughly like vilt, with the final consonants compressed

A few important pronunciation notes:

• The j in vejr- helps create a diphthong-like sound.
• The r in Danish is usually not pronounced like a strong English r.
• In vildt, the d is not usually pronounced like a clear English d.
• Danish pronunciation is often much softer and more reduced than the spelling suggests.

So the whole sentence is smoother and less sharply pronounced than an English speaker may expect.

Yes, grammatically you can. It means The weather is very wild.

Other common intensifiers are:

• virkelig = really
• ret = quite
• helt = completely / really
• så = so

Examples:

• Vejret er virkelig vildt.
• Vejret er ret vildt i dag.
• Vejret er helt vildt.

In spoken Danish, helt vildt is especially common and expressive.

You add ikke:

• Vejret er ikke vildt. = The weather is not wild.

In a simple main clause, ikke usually comes after the verb and after short predicate material like this.

So the pattern is:

subject + verb + ikke + adjective

In Danish, yes/no questions usually invert the subject and verb:

• Er vejret vildt? = Is the weather wild?

That is very common and straightforward:

• statement: Vejret er vildt.
• question: Er vejret vildt?

You mainly change the verb er.

• Vejret var vildt. = The weather was wild.
• Vejret bliver vildt. = The weather is becoming / will get wild.
• Vejret vil være vildt. = The weather will be wild.

The adjective vildt stays the same here because vejret is still a neuter singular noun.

Yes, but it is not exactly the same structure.

• Vejret er vildt. = The weather is wild.
• Det er vildt vejr. = It is wild weather.

The first sentence talks about the weather as the subject. The second uses det and names the kind of weather.

Both are natural, but they are built differently.