Is there a way to manually influence the weather somehow? And if not, is there a specific schedule or time frame in which the weather changes?
I think there is a way to change it manually, I found this video by Austin John about how to get a gigantamax Pokemon in 5 or less minutes if you change your clock I think the weather changes too. If that wasnt what you were looking for there's another video by the same guy showing the months you can get diff weather. I might be wrong about the first one and I don't remember the vid for the second but if I do i'll comment it