This sweater is a really great quality, thick fleece. Keep in mind it IS still fleece, even with the thickness, the wind does cut through it. A thin windbreaker overtop of it will definitely be necessary for a cooler/windier day. Even with a thin sweater underneath I felt a bit chill (it was about +6 and the wind wasn’t strong). However, my little guy seemed pretty toasty. Like other reviewers had mentioned, it does run small. I am typically a s-m in street clothes and I ordered a large. I was able to put a thin zip up under it, and still have a bit of room for my babe to grow (he’s only 10 days fresh - using a Tula). I think this will work well for what we need (I wouldn’t be taking the kids out in super cold winter weather anyway - but I will likely still invest in a windbreaker to go overtop). The cowl neck is gorgeous, but does feel bulky when rolled down, Overall, very happy with the product!