It's a grey Tuesday in late August. The worst of the summer heatwave is out of the way, making space for what would turn out to be a very wet start to the autumn. The perfect tonic? A chat with a Norwegian pop star who embodies sunshine. Dialling in from a trendy district of Oslo, Sigrid immediately brightens up these shores, beaming as she sips lemonade and eats what looks like a particularly tasty artisan sandwich.

"I'm having a really great day," she grins. "I'm out at my local café with one of my best friends, there are dogs everywhere, it's very cute, very picturesque – we're hanging on to the last days of summer!"

All of this positivity comes as no surprise for anyone familiar with Sigrid, someone who lights up any stage she graces, exudes pop star quality, and has a knack for writing addictive pop songs with huge-hearted lyrics, and it all comes as she's grappling with the devastating possibility of a new allergy to white wine, so truly nothing can kill her vibe (see what we did there?!).

Shining bright in spite of the drawbacks is the basis of her exceptional third album, 'There's Always More That I Could Say', a record that slides from exuberant pop bangers to breaking piano ballads before bursting back with crunchy electronic anthems. Her ability to turn her hand to songwriting cross-genre, never being held back by expectation, is what has made her such a force to be reckoned with, gaining her fans from across the musical spectrum.

It's no surprise, then, that she found herself featured on Bring Me The Horizon's 'Bad Life', announced her rock-adjacent single 'Fort Knox' on famous metalhead Jack Saunders' Radio 1 show, and took up a spot on rock festivals across Europe throughout the summer.

"I remember getting offers to play rock festivals this summer and thinking 'that's fun' but worrying nobody was going to show up because I hadn't released any music for a while or announced the album yet. But then we played Rock Werchter, and the tent is packed – there's 20,000 people out there with another 8,000 waiting to get in!"

"I've always been inspired by rock," she continues. "I've naturally gravitated towards things that are shouty and energetic but have a message or something you have to get off your chest. It doesn't have to be super deep, but there's just this energy to it. The first band I loved was Nirvana; there's actually a video of me singing 'Smells Like Teen Spirit' in the seventh grade, which was the first time I sang live!"

It's this commitment to energy – to bombastic, cathartic tracks that help both her and her fans process whatever it is that they need to heal from – that finds itself peppered across 'There's Always More That I Could Say'. Refusing to stay in one place too long, it represents an artist fully in control and totally unbothered about what you think of her.

Flipping from her well-founded, soaring vocal in sweeping finale 'Eternal Sunshine' and title-track 'There's Always More That I Could Say', to a more playful, spoken style in 'Kiss The Sky' and 'Fort Knox', Sigrid is telling the story of her life so far – exploring the beauty of friendship, the pain of relationship breakdowns, and an overwhelming sense of hope that she distils so perfectly. She's never sounded more confident, more liberated, and it makes this third album not just another wonderful Sigrid record, but the jewel in her crown.

"I love this record," Sigrid states. "This is my favourite album."

"It's crafted with so much love and attention to detail. It's a deadass serious album, but it's also a funny one. I take the piss out of myself a lot, and some songs sound a bit stupid but are smart at the same time. It's just a fun record; I just love it so much!"

The sonic details – whether in the form of Peter Bjorn and John-inspired drums on 'Jellyfish' (one for all the FIFA 08 fans out there), lo-fi synth-pop on 'Hush Baby, Hurry Slowly', or the simply massive pure-pop opening track 'I'll Always Be Your Girl' – are matched by the mechanical elements that help expand on the emotions that thread this album together, most obviously seen through the tracklist.

"I've worked really hard on creating this journey sonically and lyrically, but also with placing songs in the right place. It's explaining how chaotic it is going through a break-up; it's not straightforward, it's a lot of turns and twists and one step forward and five steps back, but it's also a really funny journey too!"

And that's the real heart of the record: fun. In fact, that's really been the heart of Sigrid's career so far. Her breakout single, 'Don't Kill My Vibe', was a tongue-in-cheek jab at a producer who tried to dictate her journey, while her other hits, 'Strangers', 'Don't Feel Like Crying', and even 'Head on Fire' with Griff, all highlight her ability to transform emotionally fraught topics into unadulterated pop classics.

The difficulty that came with even choosing singles for this album cycle, though, shows that Sigrid is only growing stronger.

"I don't want to sound cocky, but it was really hard to pick singles for this campaign because all the songs are great," she grins. "I feel like it's the first album I've written where I genuinely feel like there's no fillers."

"But 'Jellyfish' is one of my favourite songs on the record, if not the favourite, because it's a song about friendship. I think that it is so important to have a song about friendship on a record that is a lot about love, because who's there for you when the shit hits the fan?"

"It's also one where I was having fun recording it and not focusing on singing perfectly – people know I can sing, I know I can sing, I don't need to prove that to anyone. We recorded in a cosy attic studio about five minutes from here, and it felt like something new, something different. And then having 'Fort Knox' next was like boom! This feels like a part of my DNA."

In case it wasn't clear already, Sigrid isn't interested in creating something you've heard before, and she's certainly not interested in playing by someone else's rules. Part of the joy she found in making this record was discovering new ways to be creative, using every inch of her twelve-year career to dissipate writer's block and give some old ideas a second chance.

"The worst thing a person can say to me when I walk into the studio is, 'You should make another 'Don't Kill My Vibe','" she explains. "Because that's not how it works; I couldn't write a song like that now because it wouldn't be authentic – I'm not the same person I was when I wrote that song."

She continues: "The writing session culture in London, LA, even in Oslo – where you walk into a studio with two new people and the ambition is to have a fully finished produced demo with lyrics, melody, and initial production done – made me the writer I am today, but it got to a point last year where I was really tired from writing in that way."

"So I put the process on hold for a bit because I was just tired. I just couldn't see the vision. I had a few songs finished, but it wasn't until last summer that I properly discovered 'Jellyfish' and thought there was something there. I went into the studio with Askjell Solstrand, who I wrote 'Dynamite' with ten years ago, and I just felt like I was a kid again. There was no pressure. We didn't have to finish a song in a day. It just didn't fucking matter if I made a banger or not. That's when the album really came together."

In this way, 'There's Always More That I Could Say' became simply a part of Sigrid's life instead of a forced project. It was an album born of passion, not productivity. Instead of grinding out tunes in a high-pressure stop-off at a writing camp, songs grew out of everyday experiences and inspirational moments.

"Askjell is the kind of producer where he'll say, 'I feel like sitting in the park and work on the drums'. So we'd get sweet buns and coffee and just sit outside and get it done. We produced it in cafés with one earbud each, but also recorded 'Two Years' in a fancy studio in Tokyo. It's really inspiring to work with someone who doesn't have any boundaries."

As much as this is a new chapter for Sigrid, it is still identifiably her. Hyper-pop production often contrasts with lyrical vulnerability – even though often that vulnerability comes with sly digs and tongue-in-cheek references. The clearest example on this record comes in 'Kiss the Sky', a good old-fashioned dance-pop tune where Sigrid acknowledges that she's "well aware of [her] flaws" and that she's a "parody of [herself]" – a line that came to her while experiencing a bout of road rage.

"It's weird how lines like that can come out of nowhere," she giggles. "I think people assume lyrics always come from some really deep place, but honestly, I was just getting super annoyed at this posh woman driving her Range Rover and not being thoughtful to other drivers, and I just thought to myself, 'trust me to get so annoyed about that, I'm such a parody of myself'! It's quite therapeutic to know that not everything has to come from deep within, though."

She continues: "I guess [the album] is quite introvert lyrics with extrovert production. I don't think I know how to write a happy song without mentioning something that hurt me, or even to write a sad song like 'Eternal Sunshine' and not give it a euphoric feeling. Every moment contains multitudes – there's always so many emotions taking place at once – but there's always joy in experiencing big feelings."

In spite of these moments of introspection on the record, there's no removing the heartwarming smile from Sigrid's face. At the peak of her powers, on the cusp of releasing her biggest and boldest album yet, has she reached the point in her career where doubt doesn't enter into the equation anymore?

"Oh, no, I feel the pressure!" she says candidly.

"I think I would feel pressure no matter what job I did, because that's just who I am, but I have to give myself a reality check. I'm so lucky to be doing this job, to have people excited to hear this album. Sometimes I do think, like, what actually is my motivation for doing this? And, honestly, on those days, I think it's just because I'm good at it. I'm good at writing songs, I'm good at playing live, and I'm good at creating things to create joy.

"But actually, it's because I love music, and I'm taken aback that, twelve years into my career, music still makes me so emotional. I can't fake the excitement I have at going on stage, or the stars in my eyes when I think about all the songs that are yet to be written as well – y'know, there's always more that I could say!"

There are occasions, with some artists, where it's possible to sit back and think: who would've thought they'd make it this far? Sigrid is the opposite. From the minute she burst onto the scene – all white T-shirts, blue jeans, and pop anthems – it was clear she was only ever destined for the top. Even now, as she tries to come to terms with turning 29 soon, the mission is the same as it's ever been: "I want to have fun."

"That's the one thing I said to my team: I'm happy to work hard, but fun is the most important thing for this album. I want it to feel joyous. I want to tour and play festivals but also hang out with my friends and just enjoy the process because I'm so lucky to be in this position."

In one of the final lyrics of this triumphant third record, Sigrid sings: "I want eternal sunshine". There's no reason to doubt that 'There's Always More That I Could Say', with all of its sparkling energy and determined hope, can give her exactly that.