"It rains a lot in November."
Translation:Det regnar mycket i november.
For one thing, with days of the week we use på, and with months we use i. So we say på måndag but i november.
Those are two of the most frequent prepositions in Swedish and they have so many meanings it's hard to give a short explanation, but generally i is like in, and på is like on, with some difference in usage of course.
Allow me to make you happy then! ;)
Många is used with countable nouns, while mycket is for uncountables. Thus, you say "många bilar" (many cars) but "mycket bröd" (a lot of bread). In the sentence above, however, mycket is an adverb, describing the action of raining. "Många" can't be used as an adverb.