There is some amazing tech built into this jersey. The moment you put it on, you instantly feel the warmth all over. It has the weight summer jersey but it is also warm. However, it’s almost see through and it won’t block wind so I would categorize this as a 50-60 degree day jersey. Any wind would negate any warmth it trapped. It’s almost like a thin base layer with pockets. I was looking for a cold weather jersey one that would handle 40 degree weather. I would need to wear a jacket with this or a thermal base layer…but still, the wind would cut right through this so owning this is a huge, expensive compromise for me. If you have money to burn, this is for you but if you’re looking for truly functional, cost effective cold weather riding gear, you may want something much warmer. I live in the northeast so low 40 is common riding weather. I hope specialized lists more accurate temperature ranges for their winter riding gear so people buy the right thing, the first time.