I have never worn a sweater when visiting St. Martin/St. Maarten, but we usually visit in November and April and temperatures are warmer then. We have gone also in February and March and found the winds cooler then, but not cold enough for a sweater. If you find it cold, rum helps! <img src="http://www.traveltalkonline.com/forums/images/graemlins/Grin.gif" alt="" />