Fireworks illuminated the skies across Asia and millions of families gathered together today to usher in the Year of the Horse.

Residents everywhere from China's small towns and villages to its sprawling megacities rang in the Lunar New Year, the country's most important holiday.

Many of them were among the hundreds of millions of people, including 245 million migrant workers, who had crammed planes, trains and buses to return to their hometowns in what is the world's largest annual human migration.

Chinese communities across Asia also came together to celebrate, marking the holiday with flowers and offerings.

Hong Kong is due to hold a massive fireworks display over Victoria Harbour tomorrow, the second day of the new year.

In Sydney, which regularly hosts one of the biggest new year celebrations outside mainland China, a parade scheduled for Sunday night featuring 2,700 performers and 32 floats is expected to draw more than 100,000 people.

The lunar calendar is based on the cycles of the moon.

Chinese folklore ascribes 12 animals, one for each year in the rotating cycle.

In China, the horse is traditionally associated with loyalty and energy, and is considered the second-most popular animal sign of the zodiac, after the dragon.

Chinese President Xi Jinping, clad in a black coat and black fur hat, made a Lunar New Year's Eve appearance at a winter fair in Inner Mongolia.

"I wish good health, happiness for you and your families and may all go well with you," he said, according to the official Xinhua news agency.