Topic of the Week for Fall into Autumn Swap

Topic of the week for the the Fall into Autumn Swap: Now that in some geographic locations the weather is starting to turn cooler, do you change the type of yarn(s) you knit/crochet with? If so, what do you now knit/crochet with instead and why? If not, why do you not switch and what do you knit/crochet with?

I don't happen to switch yarns during change of seasons. When it gets colder, warmer, etc. I don't really change what I knit with. I knit with what I like and what I can knit with and just hope to get the opportunity to knit with something unique and different. When I first started on my knitting journey, all there was for someone like me was acrylic. See I am highly allergic to all animal fibers and that includes wool, cashmere, alpaca and, yes, silk. All that was left when I was younger was acrylic from Woolworth's (Anyone remember that place? Gosh I miss it). Now when the manufacturers come out with these wondrous organic cottons, cotton blends, corn, soy, bamboo, yes Jessi, Anne, and Chan, even linen and hemp I have to buy them and try them. So, back to the question, I really only switch yarns when someone comes out with a new yarn or i hear about a new yarn like Rowan Calmer. Now three people have told me about that one so, I need to try it. Or Crystal Palace Panda, a bunch of people have told me about that one and I have fallen in love with the Seascape color but have yet to try it.