This is the 609th most frequent Swedish word.
sådant
"Such" or "things like that."
Here, 'sådant' is used to refer to a quality or type of thing (in this case, weather), indicating a specific kind that has been discussed or is understood from the context.
Sådant väder gör mig glad.
Such weather makes me happy.
In this sentence, 'sådant' refers to a peculiar or notable type of thing that the speaker has not encountered previously.
Jag har aldrig sett sådant förut.
I have never seen anything like that before.
In this usage, 'sådant' is a pronoun referring to categories or examples of things, often followed by a specification through 'som' (like).