Iceland is amazing. You will love it. Yes, there will probably be snow in December, though the climate is changing everywhere. Iceland is relatively small but has very different geological wonders so close to each other. There are gysers, water falls, ice bergs, volcanoes, glaciers, all on a rather small Island. The main city is lovely, classy though relatively small. Bring warm clothes and lots of money. You can read more about Iceland here.