The misery of extreme weather which has struck countries across the world will be temporarily banished as billions of New Year revellers will welcome 2011 in a global blaze of fireworks and parties.
Some 1.5 million people will cram Sydney's foreshore for fireworks on the iconic Harbour Bridge, while further north in Australia hundreds of thousands battle devastating floods which have left vast swathes of land under water.
In Europe, crowds will throng landmarks like London's Big Ben and the Eiffel Tower, following a big freeze which paralysed travel and cut power and water supplies for tens of thousands.
And New York workers were scrambling to plough snow out of Times Square for the famous New Year countdown, after a "Snowpocalypse" blizzard dumped some 32 inches (80 centimetres) on the city and surrounding areas.
Party-goers carrying blankets and camping equipment started descending on Sydney harbour more than 12 hours before the fireworks display at 1300 GMT, while scantily-clad revellers packed popular Bondi Beach.
Extreme, 43 degrees C (109 F) heat brought the risk of wildfires near Adelaide, while thunderstorms threatened to cancel Melbourne's official fireworks celebration.
The tiny Pacific nation of Kiribati, just east of the international dateline, will be the first to welcome in 2011 at 1000 GMT. The deeply religious community of about 6,000 will mark the occasion with village church services.
In New Zealand, which has experienced a mild heatwave over the festive period, a fireworks spectacular is planned in Auckland as part of a celebration themed "Hot in the City".
Further south in Christchurch, hit by a powerful earthquake in September, officials only approved celebrations after late checks and modifications, including removing the city cathedral's crucifix in case it falls on revellers.
In Asia, about 400,000 were expected at a glittering fireworks-and-laser display along neon-lit Hong Kong's harbour, while millions of Japanese will visit Shinto shrines to "purify" their sins.
Although Lunar New Year is a much bigger event in the continent, thousands will brave Beijing's cold for the countdown at an upmarket shopping centre, while about 7,000 were expected at a kite-flying event in central Shanghai.
Thousands of people will jam Hanoi's Hoan Kiem Lake for midnight, while the "Bangkok Countdown" in a glitzy mall -- scene of major anti-government protests this year -- is the centrepiece of Thailand's celebrations.
Revellers in Indian financial and entertainment capital Mumbai -- scene of a 2008 attack that killed 166 people -- were given the go-ahead to party through the night, despite intelligence about a possible New Year militant strike.
Meanwhile 250,000 people will throng the banks of London's River Thames to hear Big Ben chime the last midnight of 2010, the traditional sound of the British New Year.
Millions of others will crowd landmarks like Rome's Colosseum and the Brandenburg Gate in Berlin, as well as Paris's Champs Elysee and the Puerta del Sol in Madrid.
Earlier, organisers were forced to cancel a giant January 1 snowball fight in Berlin after 8,000 signed up, while in New York this week, people wrote down and shredded bad memories of 2010 in Times Square for "Good Riddance Day".