Heralding the start of the annual River Hongbao light-up last night was a sudden but brief cloudburst of rain, minutes before the arrival of guest of honour Prime Minister Lee Hsien Loong.

It was a fitting welcome to the Year of the Monkey, as an MC quipped afterwards - because the Teochew word for "rain" sounds like "monkey" in Mandarin.

Now into its 30th year, the annual Chinese New Year celebrations by the river were launched by Mr Lee, who kicked off this year's light-up by fitting a key into a giant revolving lantern. Dances, community singing and a fireworks display rounded off the opening night.

River Hongbao 2016 runs until Feb 14 on and around The Float @ Marina Bay. In line with the Year of the Monkey, this year's theme is the Chinese classic Journey to the West, which stars monkey god Sun Wukong.

The event features its largest lantern display with over 60 pieces, including an elaborate mountain of flowers and fruit, and the regular crowd-pleaser, the God of Fortune. Visitors can enjoy a multicultural food street and local and overseas performances each night, with themed nights such as xinyao - a local genre of songs from the 1980s - on Feb 11, and getai nights on Feb 12 and 13.

To mark its 30th anniversary, an exhibition of photos from River Hongbao through the years is also being held.