Something weird that I have noticed is that my hair seem to get more mineral/hard water buildup during winter. I have used the same stuff as in summer, but still I get more build up from the water. Kinda odd.
I have also noticed that once my hair got really healthy I can do much more with it than before and it still stays healhty. This is probably the best winter I have had when it comes to my hair. I guess maybe I have found good products, got down a routine that works and I haven't used bad products for so long (2½ years now) that my hair is handling the cold better.