A heavy morning downpour yesterday gave way to bright afternoon skies, as people across Singapore turned out in full force for jubilee events on the eve of National Day.

Some were up even before the crack of dawn. From 5.30am, 120 volunteers at Eunos Community Centre toasted bread, spread butter and kaya, and cooked scrambled eggs, churning out 1,800 breakfast sets for needy residents.

They then braved torrential rain to deliver the breakfasts to beneficiaries from 50 organisations, including Trans Family Service Centre (Bedok) and Ju Eng Home for Senior Citizens.

Food also brought locals and foreigners together at a cookout, organised by social enterprise Geylang Adventurers, for migrant workers at their Woodlands dormitory.

The 80 foreign workers and 40 Singaporean volunteers whipped up dishes such as curry chicken and mee rebus, and took part in a watermelon-carving competition.

Geylang Adventurers founder Cai Yinzhou, 24, who is helming a second cookout tomorrow, said he wanted "to commemorate the lesser-sung heroes who have built our nation in a physical way".

For instance, he said, a Singaporean participant had discovered that his new flat was a project the migrant workers in his cooking team had worked on. "He got to say 'Thank you for building my HDB'."

The stormy morning raised concerns about the weather prospects for today's National Day Parade (NDP), which begins at 5.40pm. Last night, the National Environment Agency's website predicted thundery showers after 6pm.

Responding to media queries, the NDP executive committee said the parade "will proceed as planned if there are passing showers over the Padang". However, in the event of inclement weather, including heavy rain or high lightning risk, the committee "may decide to truncate certain parts of the parade".

In another statement yesterday, it added that the NDP backdrop and the decorations on the National Gallery facade will remain up until the end of tomorrow, to allow more people to take photos.

Despite yesterday's wet start, the afternoon saw the sun beating down again, as the slopes around the Botanic Gardens Symphony Lake filled up with picnickers eager to catch the Singapore Lyric Opera performing numbers such as the National Day classic Home.

IT executive Wong Yew Seng, 42, who was there with his wife and daughter, said: "I think the country has come a long way, compared with 50 years ago."

Asked what his SG50 wish was, he said: "Better public transport."

The clear weather held up through the evening, as more than 3,200 diners at a National Day dinner in the open field beside Punggol MRT station stuck SG50 tattoo stickers on their hands, in an attempt to set the local record for "Largest Gathering of People with Tattoo Stickers".

The event, organised by Pasir Ris-Punggol Grassroots Organisations and attended by Deputy Prime Minister Teo Chee Hean, was Punggol's first National Day dinner, said the grassroots adviser, Dr Janil Puthucheary.

The evening closed with song and dance in Jurong Central, as a thousand volunteer performers aged five to 70 hit the streets for a mass parade, which included a musical chronicling the area's history.

The production, attended by Deputy Prime Minister Tharman Shanmugaratnam, drew on memories of past Jurong, such as the drive-in cinema. Jurongville Secondary School student Jerrold Chua, 16, who plays a national service commander in the musical, said: "I think this is a great honour... This is a once-in-a-lifetime opportunity for me to perform... for our residents."

The jubilee eve also saw birthday greetings pour in from around the world. A video released by watchmaker Hublot featured sports stars and celebrities, including sprinter Usain Bolt, Formula 1 driver Sebastian Vettel and pianist Lang Lang.

The video culminated in Brazilian football legend Pele singing a birthday song. With a laugh, he concluded: "Happy birthday, Singapura."

• Additional reporting by Lim Yi Han and Amir Hussain