Á veturna fer hún í húfu og hanska.

It means in winter or during the wintertime, usually as a general or habitual statement.

So this sentence is not mainly about one specific moment. It means something like In winter, she wears / puts on a hat and gloves.

A useful contrast:

• á veturna = in winter, generally / every winter
• í vetur = this winter

Because á veturna is a fixed Icelandic time expression.

Veturna is the definite accusative plural form of vetur (winter). Even though it looks plural, the whole expression is normally translated naturally as in winter.

This is one of those places where Icelandic does not match English word-for-word. Literally, it looks more like during the winters, but in normal English you would usually just say in winter.

Yes, fara usually means to go, but fara í is also used with clothing.

With clothes, fara í often means:

• to put on
• or to go out wearing

So fer hún í húfu og hanska means that she puts on a hat and gloves, or more naturally in English here, she wears a hat and gloves in winter.

A helpful comparison:

• Hún fer í húfu og hanska. = She puts on / goes out in a hat and gloves.
• Hún er í húfu og hönskum. = She is wearing a hat and gloves.

Because the preposition í can take either the accusative or the dative, depending on meaning.

A common rule is:

• í + accusative = movement into something / change of state
• í + dative = being in something / location / state

Here, fer í suggests movement into a state: she is putting on the clothes. So Icelandic uses the accusative:

• í húfu og hanska

If you wanted to say that she is already wearing them, you would normally use vera í with the dative:

• í húfu og hönskum

Because the meaning is one hat but more than one glove.

• húfu = accusative singular of húfa (hat / cap)
• hanska here is understood as gloves

One interesting detail is that hanska can look the same in more than one grammatical form, so context matters. In this sentence, the natural meaning is gloves, not a glove.

So the idea is simply:

• one hat
• a pair of gloves

Because Icelandic does not have an indefinite article like English a/an.

So a bare noun can mean:

• húfa = a hat
• hanskar / hanska = gloves or a glove, depending on form and context

If Icelandic wants to say the, it usually adds the definite article to the end of the noun:

• húfan = the hat
• hanskarnir / hanskana = the gloves

So í húfu og hanska naturally means in a hat and gloves or just wearing a hat and gloves.

Because Icelandic normally follows a verb-second pattern in main clauses.

That means the finite verb usually comes in the second position. If you put a time expression first, like Á veturna, then the verb comes next, and the subject follows:

• Á veturna fer hún í húfu og hanska.

If you start with the subject instead, that is also possible:

• Hún fer í húfu og hanska á veturna.

Both are grammatical. The version with Á veturna first gives a little more emphasis to the time phrase: In winter, ...

It most naturally describes a habit or a general fact.

Because of á veturna (in winter) and the present tense fer, the sentence sounds like:

• In winter, she wears a hat and gloves
• She puts on a hat and gloves in winter

It does not sound like one single event unless the context makes it specific.

So the sentence is best understood as something she does regularly when it is winter.