The coldest that we got on this trip was the night we took a private trip to see the lights. We did this from Tromso. We stood outside for such a long time since the lights were so spectacular! I strongly suggest the hand and feet warmers for your boots. We never needed big snow boots and our hiking boots were really enough. Heavy socks, warm hat that covers your ears, and the best gloves you have. It was a wonderful trip. Tromso was our favorite place.