Ready or not, the holiday season is upon us, which to many means one thing: Lots of twinkling lights to enliven those ever-increasing hours of darkness. The Christmas tree at Macy’s Downtown Crossing store is already aglow, yet there’s still plenty of other delightful, free debuts to come, beginning November 21 at 5 p.m. when locals throw the switch on the spectacular blue lights (pictured) on the trellis at Christopher Columbus Park in the North End. Revel in holiday sing-alongs and a visit from Santa while savoring cookies, hot cocoa and clam chowder. Over by the Fort Point Channel and the Boston Children’s Museum, Martin’s Park hosts its second annual holiday ceremony on November 26 from 4–6 p.m. when the ship there lights up in celebration of yuletide joy. St. Nick arrives by boat, and visitors can join in caroling, hot chocolate and other seasonal fun. On November 28 from 5–6 p.m., the man in the red suit and Rudolph put in an appearance in Copley Square for its tree lighting shindig. Tunes from the Boston Children’s Chorus, the Boston Pops Esplanade Brass Ensemble and more are on tap for the evening, as well as cookies and pictures with Santa at the nearby Fairmont Copley Plaza. All of this leads up to perhaps the most anticipated event of them all: The 81st annual Boston Common Tree Lighting. This venerable tradition—which culminates in the illumination of a giant evergreen donated yearly by the people of Nova Scotia in recognition of Boston’s help after the tragic Halifax Explosion of 1917—begins at 6 p.m. on December 1 and is highlighted by another Santa and Rudolph sighting, musical performances, appearances by the Royal Canadian Mounted Police and Mayor Michelle Wu, and closing pyrotechnics after both the Common and Public Garden lights are switched on in sequence. Feel the warm glow in person, or check out the broadcast on WCVB Channel 5, which airs at 7 p.m.