Villagers becoming less active

[Blizzard]

Is it because the weather is cooling off, or do they actually stay in more as the weather gets colder? Lately, I have one that stays on the beach in one spot all day long by himself. Everyone is inside and they don't seem to be chatting and certainly not whistling anymore. Is it me???? Be nice!!

 

[Croconaw]

I think that's just a coincidence because my villagers are always mysteriously wandering outside.