Obama has spoken about the upcoming birthday, saying that his hair is getting gray and his metabolism is slowing down.
The first family will not be with the president. First lady Michelle Obama is taking their youngest daughter, Sasha, to Spain this week and their other daughter, Malia, is away at camp. White House press secretary Robert Gibbs demurred when asked if it was a source of Obama family tension that the president was celebrating his birthday without them.
"They'll all be back together soon," the press secretary said diplomatically.
While in town, Obama will attend fundraisers for the Democratic party and visit a Chicago auto plant.
Last week first lady Michelle Obama asked supporters to sign an electronic birthday card for the president at http://my.barackobama.com/birthday
Last year, President Obama celebrated his 48th birthday by presenting a cake to White House reporter Helen Thomas, who shares the same birthday.
The Associated Press contributed to this report.
