More than 50,000 revellers are expected to watch today as One Direction, Calvin Harris, and Coldplay kick-off the extravaganza at Glasgow Green.
And partygoers who arrived in the city for Radio 1's Big Weekend refused to have their spirits dampened by the predicted rain showers.
Despite clear skies this afternoon, showers are expected to move in tonight. Temperatures are set to reach a peak of 16C this weekend.
The giant outdoor party will see dozens of big names stars including Katy Perry, Paolo Nutini, and Example perform during today and tomorrow.
Last night, a crowd of 14,000 over-18s were entertained by a packed bill of top DJs, including some of the best known names from the dance music world.
Tiesto and Pete Tong performed alongside Radio 1 DJs Annie Mac, Zane Lowe and Danny Howard in George Square.
A total of 50,000 passes for the main event sold out in just 30 minutes.
Organisers are warning partygoers that the over-18s age restriction will be strictly adhered to and people must bring ID with them.
Food and drink can not be brought into Glasgow Green, with the exception of water in a bottle with an unbroken seal. There will also be food stalls on site.
Motorists will banned from streets around Glasgow Green from 1am on Saturday morning until just before midnight on Sunday.
A council spokesman said: "Diversions will be signposted on streets around the events."