Update, 4:18 p.m.: Follow live tweets and watch live video of the tree lighting ceremony here.

If it’s December, it must be that time of year at the White House: Time to deck the halls and light the official National Christmas Tree.

President Obama and first lady Michelle Obama will attend the 89th annual lighting ceremony at 5 p.m. Thursday on the Ellipse, and the president will make remarks. Festivities will start at 4:30 p.m., with a program hosted by Carson Daly, and featuring musicians Will.i.am and OneRepublic, among others.

National Christmas Tree, 2009 (Washington Post/File)

According to the National Christmas Tree Web site, the tradition began in 1923 when President Coolidge lit a 48-foot fir tree with 2,500 red, white and green electric bulbs.

Already, the Obamas have erected and decorated the (separate) White House tree, a 19-foot-tall balsam fir from Neshkoro, Wisc., that is displayed in the Blue Room.

On Wednesday, Michelle Obama gave reporters a tour of the 37 trees and a 400-pound gingerbread house that are on display throughout the White House. But it is first dog Bo Obama who is the star of the show this year.

As Post reporter Jura Koncius writes: “Then there was Bo, truly top dog of the Obamas’ Christmas. While the Clintons offered cookies shaped like Socks the cat and the Bushes coaxed their Scottish terrier to star in holiday ‘Barney Cams,’ the Obamas put a replica of the first dog in every room. There’s a ‘topiary’ Bo made of eco-friendly trash-bag strips in the library, a Bo made of black buttons in the Red Room and black-licorice-and-felt Bos throughout the public rooms. And guess who wormed his way onto the Obamas’ holiday card this year? Bo — sitting alone by the library hearth, his famous owners nowhere in sight.”

View Photo Gallery: The national tree has changed species, locations, energy efficiencies and size, but lighting it has been a tradition since 1923.

Check out:Live coverage of the tree lighting ceremony

The Washington Post’s 2011 Holiday Guide