The sudden weather-induced change forced a scramble for hundreds of thousands of people who had spent months planning for the swearing-in of the nation’s 47th president.

The potential change, a rare break with tradition, would deny Mr. Trump the pomp and large audience he hoped for at his second swearing-in.

Bad weather forecasts mean President-elect Donald Trump will take the oath of office from inside the Capitol Rotunda and people visiting Washington from around the country won’t be able to see it in person.