Millions of people across the UK have celebrated the arrival of the New Year.
An estimated 700,000 people gathered in London - many on the banks of the Thames - to see the fireworks at the London Eye and to hear Big Ben chime.
In Edinburgh, about 100,000 revellers enjoyed the street party, with about 15,000 in Glasgow's George Square.
In Cardiff, some 30,000 people joined in the Calennig celebrations at Cardiff Castle, and 5,500 celebrated at an open-air concert in Belfast.
The firework display in London lasted 11 minutes and as it ended the crowds, who had braved the drizzle to watch, cheered and sang Auld Lang Syne.
Thousands of people also gathered in nearby Trafalgar Square, where a shaft of light was beamed on to Nelson's Column.
Albert Caminha, 27, from Portugal, said: "I thought the fireworks were incredible - every possible colour was used - and I loved the way the lights reflected in the water from the river."
Keeley Taylor, 19, travelled from Bolton, Lancs, to spend midnight in London.
"We're getting a bit wet, but everyone seems to be having a good time and there's a really good atmosphere here," she said.
Londoner James O'Shea, 32, said: "It's amazing to be in one of the world's most vibrant cities on a night like this."
Police said there had been 51 arrests in London, including 16 for drunk and disorderly behaviour.
Metropolitan Police Superintendent Andy Tarrant said in the main the crowds had been good humoured and there had been no major issues reported to police.
The Edinburgh festivities were described as "a great event"
New Year's Eve represented a peak in the number of 999 emergency calls around the country.
In the 45 minutes after midnight, 100 emergency calls were made to the West Midlands Ambulance Service, most of which were related to "alcohol-fuelled incidents", a spokeswoman said.
There was a rise of one-sixth in the number of calls received by the London Ambulance Service between 0000 and 0400 GMT, compared to last year. More than 1,800 calls were received during that period.
A further 1,000 people dialled 999 in south-west England, a total which was similar to previous years.
'All the stops'
Last year high winds meant the cancellation of celebrations in Edinburgh, Glasgow and Stirling.
But this year's Edinburgh festivities were described as "a great event" despite the damp weather.
At midnight the fireworks display lit up the sky above the city and the gun was fired from the castle ramparts.
Mark Hudson, 31, from Sydney, said: "I've come to the Hogmanay party because I've heard it's one of the best celebrations in the world.
Edinburgh's fireworks lit up the sky around the castle and Princes Street
"I think tonight is going to be extra special because of the cancellation last year and I think they are really going to pull out all the stops."
X-Factor winner Leon Jackson had been due to open the Hogmanay street party, but had to pull out with tonsillitis.
About 9,000 people attended the nearby Concert in the Gardens event, where a song was dedicated to Motherwell captain Phil O'Donnell, who died after collapsing during Saturday's match against Dundee United.
About 350 officers from Lothian and Borders Police patrolled the street party area, and police said there were four arrests for minor offences.
Elsewhere there were more fireworks in Birmingham, a free concert in Liverpool and a New Year's Gala in Bristol.
More rail delays
Up to half a million people are expected to watch the annual New Year's Day Parade in London later.
More than 8,000 performers from many nations, including 3,000 from the US, are set to travel the 2.2 mile route, and a message from the Queen will be read out.
But thousands of rail passengers travelling on New Year's Day are facing delays after over-running engineering work was extended by another day.
The work affects Virgin Trains to and from the West Midlands, Scotland, north Wales and north-west England.
Services will now not return to normal until 0530 GMT on 2 January.