Winter cold is the driving force behind the annual HarborFrost festival in Sag Harbor, 1 to 6 p.m. Saturday, Feb. 24. The outdoor festivities include an ice-carving demonstrations, ice sculptures along Main Street, fire jugglers, a soup supper ($5 a bowl) at Old Whaler’s Church and a Frosty Plunge at 2 p.m. At dusk, fire dancers and fireworks by Grucci will light up the harbor.