These boots come in whole sizes only, so I ordered up, as I like to wear layers of socks to wick moisture and replace the foot bed insert with a better arch support. I have not worn these in any deep snow yet...we haven't had any, but used them in cold (15 degree)conditions and my feet were warm. I live in Wisconsin, so it is only a matter of time before the snow thing happens. Meanwhile, and most important, they are adorable!!!! I will update if they fail in wet conditions.