It's not as cold as you would expect. We were there in early August and I remember wearing jeans, short or long sleeve shirts and a medium weight jacket. If you go ashore to shop/explore be sure to wear sturdy shoes or boots. There are a lot of puddles and or mud around so sandals are definitely out!
Edited to add, if you like to cook check out the Ulu Knives. I picked one up and it works really well!