Island Weather ENJOY the LIVE VIEW of Nantucket Harbor! From the Nantucket Whaling Museum Roofwalk, Nantucket Historical Association. Winter Weather Advisory Issued:4:13 AM EST on February 18, 2019 Expires:4:00 PM EST on February 18, 2019 Monday 02/18 90% Snow Occasional rain. Some snow showers mixing in for the afternoon. Areas of freezing rain possible. High 39F. Winds NE at 10 to 20 mph. Chance of precip 90%. Tuesday 02/19 0% Partly Cloudy Partly cloudy skies. High 28F. Winds NW at 15 to 25 mph. Wednesday 02/20 0% Overcast Cloudy. High 29F. Winds NNE at 10 to 15 mph.