Dec 7, 2016. Plan a trip in mid-January to attend the 43rd Stowe Winter Carnival, a seasonal celebration complete with ice carving competitions. When is the winter season in Iceland? What are the best things to do in winter in Iceland?. 7 Day Northern Lights Self Drive Tour | Destination Ice Cave. Public Holidays (2019) DATE HOLIDAY Information January 01 New Year's Day April. during weak La Niña conditions in…