President Obama's 2nd Inauguration Countdown It is the biggest event in washington. It happens once every four years. The countdown to inauguration is on. When president obama takes the oath of office on monday, the inaugural celebration will be nothing compared to what it was back in 2009 when he was sworn in. Abc's david kerley is in on with more. Reporter: Bianna and dan, this is my third one. It gets cold every time the president gets ready to take the oath. While the weather is going to be the same, this is going to be a much different celebration than the one four years ago. &#9834; the barricades are up. The viewing stands, built. The finishing touches going on floats. Members of the military have already practiced parading. I -- Reporter: And he's ready to take the oath a second time. &#9834; At last &#9834; Reporter: Beyonce and james taylor will perform. But this will be a very different affair. Four years ago, 1.8 people filled the less than half that number, just 800,000, are expected this year. Four years ago, nearly every one of the 29,000 hotel rooms here were booked. 7,000 rooms are available this morning. Only two inaugural balls, versus ten four years ago. All after an expensive campaign, a tough economy and four years. Just the moment that that was for the country, the first african-american president. And it was new for everyone. There still is a level of excitement despite the numbers. As we move down pennsylvania avenue. Reporter: Already fortress d.C. Is taking shape, a lockdown, as the president talks to historians about hitting the right tones in what will be his last inaugural address. Despite the fact this is going to be a much smaller affair, it's going to be a lot of EXCITEMENT, AS anita McBride said. The number of people, nearly double who came to the second inaugural for president bush and president clinton. Still, that remarkable drop-off from the last time. David kerley, thank you very much. Stay warm. And our special coverage of the inauguration starts tomorrow on "gma." And abc news live coverage of the ceremony on monday, starts at 7:00 eastern, with george stephanopoulos and josh elliott co-anchoring. Busy monday morning. We're going to switch gears