Philadelphia has postponed its "Holiday Celebration and Treelighting Spectacular," originally scheduled to start at 5 this afternoon.
Because of heavy rain in the forecast, the festivities have been switched to Thursday, when conditions should be cooler but clear.
This year, the city has a 38-foot-tall artificial tree, with 5,800 small LED lights and 672 silver-and-red ornaments, set in JFK Plaza (LOVE Park), amid the 50 wooden shops of the medieval-style Christmas Village. The five-star star atop the tree has 129 light by itself.
Plans include singers, performers and characters from various shows, and the tree-lighting, with Mayor Nutter and his wife, Lisa, flipping a switch just before 6 p.m.
Singing will be the Municipal Employees Choral Ensemble and the casts of two musicals in town this month and part of next - The Jersey Boys, playing at the Forrest Theatre, and The King & I, at the Walnut Street Threatre.
"Special appearances" will include the Mouse King from Pennsylvania Ballet's The Nutcracker, running all month at the Academy of Music, and characters from a movie based on Dr. Seuss' The Lorax that's set to be released in March.
Because of the LED lights, the tree will use about a quarter of the power of conventional lighting for a tree that size - about as much as a common household refrigerator would use, said spokesman Randy Giancaterino.