The Obamas at the National Christmas Tree Lighting ceremony on the Ellipse in 2013. (Marvin Joseph/The Washington Post)

Christmas is still three months away, but the lottery for tickets to the lighting of the National Christmas Tree opens next week.

The tickets are free, but viewers must enter a lottery to get them. The National Park Foundation and the National Park Service said the lottery will open at 10 a.m. Oct. 7 and run until 10 a.m. Oct. 10.

The tree lighting ceremony will take place Dec. 1 at the White House Ellipse in President’s Park. Winners of tickets in the lottery will be contacted Oct. 27.

The park service also announced that performers for the ceremony will include Chance the Rapper, Kelly Clarkson and Yolanda Adams. It will be the 94th lighting of the tree. And this year’s lighting will also cap the centennial celebration for the National Park Service.

The tradition began when President Calvin Coolidge lit a 48-foot fir tree in 1923. It was decorated with 2,500 red, white and green electric bulbs.

Over the years, the tradition continued with memorable moments. In 1934, two Fraser fir trees were planted in Lafayette Park near the statue of Andrew Jackson in hopes that they would be used as the National Christmas Tree.

When President Harry S. Truman lit the tree in 1945 after the end of World War II, he said, “This is the Christmas that a war-weary world has prayed for through long and awful years.”

“With peace come joy and gladness,” he said. “The gloom of the war years fades as once more we light the National Christmas Tree.”

Since 1954, the National Christmas Tree has been decorated by Hargrove, the professional event decorating company in Lanham. Hargrove was known for manually installing every socket and testing every bulb to make sure they worked.

In the 1970s, the two live trees planted on the Ellipse died, and, over the years, trees have been brought in from elsewhere for the tradition. Over the past few years, the tree has had LED lights to make the decorations more energy efficient.

For information, go to thenationaltree.org.