In Mumbai and states down south, I don't particularly recall a winter uniform ever. To be honest, in my school days I don't ever recall wearing any winter clothes..there used to be just a nip in the air no real cold weather... I now hear of people saying that it's getting colder but I never recall any such growing up memory.
I remember feeling a bit upset those school days because we never had a blazer for a uniform while I used to see my family friend's kids have one... 😆