Revelers around the globe are bidding farewell to a decade that will be remembered for the rise of social media, the Arab Spring, the #MeToo movement and, of course, President Donald Trump.
A look at how the world is ushering in 2020:
Children watch fireworks along a street during New Year's Eve celebrations in Manila, Philippines, 01 January 2020.
More than one million people gathered on a hazy Sydney Harbor and surrounding areas ahead of ringing in the New Year despite the ongoing wildfire crisis ravaging New South Wales, Australia's most populous state.
The 9 p.m. fireworks over Sydney's iconic landmarks were briefly delayed due to strong winds, but revelers clearly enjoyed themselves in a desperately needed break for the state.
New South Wales has encountered the brunt of the wildfire damage, which has razed more than 1,000 homes nationwide and killed 12 people in the past few months.
Russians began the world's longest continuous New Year's Eve with fireworks and a message from President Vladimir Putin urging the country to work together in the coming year.
Putin made the call in a short speech broadcasted on television just before the stroke of midnight in each of Russia's 11 time zones. The recorded message was followed by an image of the Kremlin Clock and the sound of its chimes. State TV showed footage of extensive festive fireworks in the cities of the Far East.
But one holiday tradition was missing in Moscow this year – a picturesque layer of snow. The Russian capital has had an unusually warm December and temperatures in central Moscow as midnight approached were just above freezing.
Revelers, as well as pro-democracy protesters, flocked to sites across Hong Kong to usher in 2020.
The semi-autonomous Chinese city has toned down New Year's celebrations amid the months-long demonstrations. The protests have repeatedly sparked violent battles with police and have taken their toll on Hong Kong's nightlife and travel industries.
A fireworks display that traditionally lights up the famed Victoria Harbor was canceled amid safety concerns, while some roads were closed and barriers set up in the Lan Kwai Fong nightlife district to control crowds.
People flocked to temples and shrines in Japan, offering incense with their prayers to celebrate the passing of a year and the first New Year's of the Reiwa era.
Under Japan's old-style calendar, linked to emperors' rules, Reiwa started in May, after Emperor Akihito stepped down and his son Naruhito became emperor.
Although Reiwa is entering its second year with 2020, Jan. 1 still marks Reiwa's first New Year's, the most important holiday in Japan.
Stalls at Zojoji Temple in Tokyo sold sweet rice wine, fried noodles and candied apples, as well as little amulets in the shape of mice, the zodiac animal for 2020. Since the Year of the Mouse starts off the Asian zodiac, it's associated with starting anew.
Tokyo will host the 2020 Summer Olympics, an event that is creating much anticipation for the entire nation.
People wright their new year's wishes on votive wooden tablets or "Ema" after offerring prayers at the Meiji Jingu Shinto shrine as they celebrate the arrival of the year 2020, Wednesday, Jan 1, 2020, in Tokyo. (AP Photo)
Tens of thousands of revelers in Indonesia's capital of Jakarta were soaked by torrential rains as they waited for New Year's Eve fireworks while others in the country were wary of an active volcano.
Festive events along coastal areas near the Sunda Strait were dampened by a possible larger eruption of Anak Krakatau, an island volcano that erupted last year just ahead of Christmas Day, triggering a tsunami that killed more than 430 people.
The country's volcanology agency has warned locals and tourists to stay 2 kilometers from the volcano's crater following an eruption Tuesday that blasted ash and debris up to 2,000 meters into the air.
New Zealand's major cities greeted the New Year with fireworks as the nation appeared happy to be done with a year filled with challenges, both natural and man-made.
On March 15, a lone gunman killed 51 people and wounded dozens at two mosques in the South Island city of Christchurch. In December, an eruption of the volcanic White Island off the east coast of the North Island killed at least 19 tourists and tour guides.
Londoners were making their way to the banks of the River Thames to jostle for the perfect spot to watch a spectacular fireworks display launched from the London Eye and from barges near Parliament.
The familiar chimes of London's Big Ben clock tower rang in the New Year, even though they have been silent for most of 2019 because of extensive restoration work.
To the north, the multi-day Hogmanay New Year's celebrations in Edinburgh began Monday night with a torchlight parade through the streets of the Scottish capital. Security was tight in both cities and elsewhere in Britain following a recent terrorist attack on London Bridge that claimed two lives. Police arrested five men on suspicion of terrorism offenses Monday but said the arrests were not related to the London Bridge attack or to New Year's Eve celebrations.
Hundreds of thousands of revelers are expected to ring in the New Year in front of the Brandenburg Gate in Berlin.
Several German cities including Munich and Hamburg have banned private fireworks amid concerns of danger and environmental impacts from the increasingly powerful fireworks. A recent poll by the Forsa research institute found 59% of Germans would support a ban on private fireworks in city centers, while 37% were opposed.
Thousands of South Koreans filled the cold downtown streets in Seoul ahead of a traditional bell-tolling ceremony near City Hall to send off an exhausting 2019 highlighted by political scandals, decaying job markets and crumbling diplomacy with North Korea.
Dignitaries ringing the old Bosingak bell at midnight included South Korean Major League Baseball pitcher Hyun-Jin Ryu and Pengsoo, a giant penguin character with a gruff voice and blunt personality that emerged as one of the country's biggest TV stars in 2019.