I oktober blæser det ofte meget, så jeg tager en varm jakke på om morgenen.

In Danish, months normally take the preposition i for in:

• i oktober = in October
• i januar = in January

You do not use an article with month names in this kind of expression, so oktober stands alone.

A useful extra note: month names are normally not capitalized in Danish. It is written Oktober here only because it is the first word of the sentence. Otherwise it would usually be oktober.

This is because Danish follows the V2 rule in main clauses: the finite verb normally comes in the second position.

Here, I oktober is placed first. That takes the first slot, so the verb must come next:

• I oktober | blæser | det ofte meget

If there were no opening time phrase, the normal order would be:

• Det blæser ofte meget i oktober.

So blæser det is not unusual here—it happens because I oktober has been moved to the front.

No. In weather expressions, det is often a dummy subject, just like English it in:

• It is raining
• It is windy

So in det blæser, the word det does not refer to a real object or thing. It is simply required by the grammar.

This is very common in Danish weather expressions:

• Det regner = It’s raining
• Det sner = It’s snowing
• Det blæser = It’s windy / It’s blowing

Here, ofte means often, and meget means something like a lot / strongly / very much.

So:

• blæser det ofte meget = it is often very windy / it often blows a lot

The idea is:

• ofte tells you how often
• meget tells you to what degree

This word order is natural in Danish. It keeps the frequency idea first and then adds the degree.

Be careful not to confuse this with meget ofte, which would mean very often. In your sentence, meget does not modify ofte; it modifies the idea of blowing.

Because så here means so, as a coordinating conjunction linking two main clauses:

• I oktober blæser det ofte meget, så jeg tager en varm jakke på om morgenen.

After this kind of så, the second clause keeps normal main-clause order, which here is:

• jeg tager ...

So:

• så jeg tager ... = so I put on / so I wear ...

By contrast, Så tager jeg ... can also exist, but then så usually means something more like then, and it counts as the first element of the clause, triggering inversion:

• Så tager jeg en jakke på. = Then I put on a jacket.

So the difference is:

• så jeg tager ... = so I ...
• så tager jeg ... = then I ...

This is a very common Danish verb pattern. The verb is tage ... på, which means to put on (clothes).

With a full noun object, the particle often comes after the object:

• jeg tager en jakke på
• hun tager skoene på

So in your sentence:

• jeg tager en varm jakke på = I put on a warm jacket

If the object is a pronoun, the pattern is usually:

• jeg tager den på = I put it on

So yes, tage på is a kind of particle verb, and Danish often separates the particle from the main verb in ordinary main clauses.

Because jakke is a common-gender noun in Danish, so it takes en:

• en jakke

The adjective must agree with the noun. In the indefinite singular common gender, the adjective usually has its basic form:

• en varm jakke

Compare:

• en varm jakke = common gender, singular, indefinite
• et varmt hus = neuter, singular, indefinite
• den varme jakke = definite
• varme jakker = plural

So varm is correct because:

• jakke is en-word
• it is singular
• it is indefinite

In Danish, expressions for parts of the day often use om + definite form:

• om morgenen = in the morning
• om aftenen = in the evening
• om natten = at night

So morgenen is definite because that is simply the standard Danish pattern in this kind of time expression.

In your sentence, om morgenen suggests a habitual meaning: in the morning / in the mornings.

Useful comparisons:

• om morgenen = in the morning / in the mornings
• i morges = this morning
• om en morgen = one morning / some morning

Danish often uses the present tense for things that are:

• habitual
• generally true
• regular actions
• near-future actions when the context is clear

So:

• I oktober blæser det ofte meget = In October it is often very windy
• så jeg tager en varm jakke på om morgenen = so I put on / wear a warm jacket in the morning

This sounds natural because the sentence is talking about a general habit, not one single future event.

English does something similar sometimes:

• When it’s cold, I wear a coat.

So the Danish present tense here is exactly what you would expect for a repeated action.

No, that would be incorrect.

With tage ... på meaning put on, the normal order is:

• tage + object + på

So you say:

• jeg tager en varm jakke på

Not:

• jeg tager på en varm jakke

That incorrect version sounds like på is introducing a prepositional phrase, but here på is a verb particle belonging to tage på.

So remember this pattern:

• Jeg tager trøjen på.
• Hun tager skoene på.
• Vi tager dem på.

Yes. Danish commonly uses det blæser where English would often say it’s windy.

Literally, blæser does come from to blow, but in weather talk it often corresponds to natural English it’s windy.

So:

• Det blæser = It’s windy / It’s blowing
• Det blæser meget = It’s very windy / It’s blowing hard

This is a good example of where a word-for-word translation is possible, but a more natural English translation may be slightly different.