Trump inauguration moved indoors amid freezing weather

US president-elect Donald Trump says his inauguration will take place inside the US Capitol rather than outdoors because of severe cold, the first time in 40 years that presidential inaugural ceremonies will be moved indoors.

"There is an Arctic blast sweeping the Country. I don't want to see people hurt, or injured, in any way," Trump said on his Truth Social platform on Friday.

"Therefore, I have ordered the Inauguration Address, in addition to prayers and other speeches, to be delivered in the United States Capitol Rotunda," Trump added.

The last time an inauguration was moved indoors because of the bitter cold was in 1985 for former Republican president Ronald Reagan's second swearing-in when the afternoon wind chill fell into the range of minus 23C to minus 29C.

The weather forecast for Washington DC on Monday predicts temperatures at the time of Trump's swearing-in to be about minus 7C but will feel even colder with wind chill.

Trump said supporters can view the ceremony on screens inside the Capital One Arena, a sports venue in downtown Washington DC that holds 20,000 people.

Trump also said his presidential parade, which was set to involve marching bands and other groups proceeding down Pennsylvania Avenue past the White House, will be switched to inside the Capital One Arena.

It was not immediately clear how a parade would be organised inside the sports venue.

Trump said he would join the crowd at the arena after he is sworn in.

Trump is due to hold a rally with supporters inside the same arena on Sunday, the eve of his inauguration.

Bitter cold has affected several past inaugurations.

William Henry Harrison, the ninth US president, delivered the longest inaugural address on March 4, 1841, in wet and cold conditions without a hat or overcoat.

That event and speech were thought to have contributed to his later succumbing to pneumonia.

He died one month after taking office, making his presidency the shortest in US history.

During the second swearing-in ceremony for president Ulysses S Grant on March 4, 1873, several cadets and midshipmen standing outside without overcoats collapsed and gusting winds made Grant's address inaudible to even those close to him on the platform, according to a history published by the National Weather Service.

The morning low temperature of minus 15C on that day remains Washington DC's coldest March day on record.