An afternoon downpour turned the festival area at the Ådalen park into a quagmire, but the Northside public embraced the wet conditions.
The festival has attracted some huge international names over the years, and 2017 is no exception. American R&B superstar Frank Ocean headlined Friday's programme, and British indie band Radiohead is scheduled to close the event Sunday.
Scandinavian acts are also key to Northside's success. Sweden's Veronica Maggio cheered up a soaked public with her uplifting pop on Friday afternoon, and Denmark's own electropop sensation MØ cranked up the atmosphere as evening set in.
Since it was held for the first time in 2010, Northside has set its sights on becoming an organic and sustainable festival.
All of the food sold at Northside's food stands and restaurants is organic, and hundreds of recycling bins around the festival area separate plastic, paper and food waste. All plastic cups are also sold against a recycling charge which is refunded when they are returned.
The festival's organisers announced earlier this year plans to become fully powered by sustainable energy, replacing diesel generators with wind and solar cells, by 2020.