It starts at 6 p.m. with a performance from Disney on Ice and then the buildings will be lit one-by-one. The Hyatt Regency will light its lobby and tree at seven tonight.
And there's another San Francisco tradition that is celebrating 25 years. Macy's on Union Square will unveil its holiday windows today, featuring adoptable cats and dogs. The store partners with the San Francisco SPCA. Last year, more than 300 animals found a new home for the holidays.