Forecasters have warned temperatures will fall below zero in many places across the UK as revellers welcome the new year.
The 100,000 partygoers in Edinburgh will need more than good cheer to keep warm with lows of minus 2C.
In London up to 500,000 are expected to attend a fireworks display, while Elton John is playing at the O2 Arena.
A range of New Year events have been planned for Cardiff, Manchester and Birmingham among others.
Freezing fog
Sub-zero temperatures are also forecast for northern England and Wales, while many other areas could also see the mercury plunge.
But revellers going to fireworks displays might not get a clear view, with mist, freezing fog and low cloud in some areas.
BBC weather forecaster Rob McElwee said the coldest weather would be in north-west England and England-Wales border areas, with temperatures dropping as low as minus 7C.
Belfast would see temperatures on New Year's Eve of minus 2C, London around zero, and Cardiff just below zero, he added.
He also explained that snow seen falling in the Leeds, Manchester and Hull areas on Wednesday was "man made" and could probably be attributed to cooling tower clouds drifting slowly downwind.
It happened last year and only occurs in certain atmospheric conditions when the tiny particles emitted by cooling towers are turned into snow crystals.
Flight delays
There is unlikely to be any let up in the cold weather for the first days of 2009.
On New Year's Day cold temperatures and lots of fog are set to persist, with thickening fog over north-west England and the West Midlands.
A little sunshine may break through in western Scotland, Wales and southern England. Spots of rain and snow may fall in north-east England and eastern Scotland, with a possibility of black ice.
By 2 January more sunshine is expected, but the cold weather will remain for the forseeable future.
Meanwhile, Britons travelling to and from Geneva have suffered delays and cancellations after the airport runway was closed due to snow for several hours on Tuesday.
Easyjet said four of its flights - from Geneva to Manchester, Belfast, Edinburgh and Newcastle - had been cancelled, and a further 26 UK connections delayed.
Although the runway has reopened there are knock-on delays of up to seven hours. Easyjet advised people travelling to and from Geneva to check flight details at easyjet.com or call 0871 244 2366.
EVENTS AROUND THE UKThe party in Edinburgh - the self-styled Hogmanay capital - has been under way for a number of days already, to build up to the bringing in of the new year.
Events will include fireworks around Edinburgh Castle, live bands and a huge singalong of Auld Lang Syne, which organisers hope will break a world record.
In Cardiff revellers will be able to sleep off their partying in an inflatable tent staffed by medics at the Millennium Stadium.
The sleepover centre has been converted from an emergency chemical decontamination tent.
And in London police are gearing up for one of the busiest nights of the year.
There will be 10 minutes of fireworks at the London Eye, on the banks of the River Thames, and on the nearby Shell building a huge projection will show music, a countdown to midnight and a speech from Mayor Boris Johnson.
The Met's Supt Brian Pearce urged people to plan their night in advance and to take extra care after consuming alcohol.
He added: "Hundreds of thousands of people used to travel to central London when there was nothing for them to see or do.
HAVE YOUR SAY"Now with such a world-class fireworks display being staged the centre of town is more popular than ever before.
"Sadly, not everyone sets out just for a fun night out.
"There are those criminals who will use the cover of crowds to commit crime, so help yourself by keeping a close eye on all your belongings."
Tube services will be running all night, but the authorities have warned people may need to queue to get into stations because the demand will be high.
And on Thursday more than 400,000 people are expected to head into London for the New Year's Day Parade.
Organisers said the traditional spectacle aimed to breathe fresh air into London by helping visitors beat the credit crunch and start the year healthily.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©
~RS~q~RS~~RS~z~RS~32~RS~)