Organizers of Rock the Garden may have been onto something when they brazenly hyped this year's one-day rock festival as "the official start of summer."

The popular annual fundraiser for Walker Art Center and Minnesota Public Radio moved to a temporary home on the Minneapolis riverfront Saturday, due to the razing of the Walker's Sculpture Garden for renovations. Mother Nature, in turn, raised the heat on the 14,000 attendees with a ferocity that made it feel like summer had arrived with a vengeance.

"Raise your hands if you're hotter than you've been all year," MPR/89.3 the Current personality Andrea Swensson said from the stage midafternoon, bright red arms and wafts of body odor filling the air in response.

A breeze was as scarce as a Justin Bieber T-shirt in the hipster-flavored music fest, which sold out two days earlier with a typically eclectic lineup headlined by Oklahoma psychedelic gurus the Flaming Lips, who paid homage to both Prince and David Bowie in a truly glowing sunset finale. Other acts throughout the day included breakout Chicago rap star Chance the Rapper, Denver soul-rock throwbacks Nathaniel Rateliff & the Night Sweats and local favorites Poliça, Hippo Campus and Grrrl Prty.

The nearly 90-degree heat was so bad, it had Ethan Riser, 27, of Minneapolis contemplating jumping into the Mississippi from the festival's riverfront VIP area. "I'm probably going to have to drink a lot more beer before I do that, though," Riser joked, as party crashers in boats listened to the music for free off shore.

In the shadow of the Plymouth Avenue Bridge with a backdrop of the downtown skyline, the replacement site Boom Island Park earned favorable reviews from fans and musicians alike. "It's a beautiful view," Rateliff noted during his band's doubly sweltering horn-driven set.

Thousands congregated at Boom Island Park Saturday for Rock the Garden, which featured performances by the Flaming Lips, Chance the Rapper, and more.

Most agreed, however, it's hard to beat the perfectly sloped hillside outside the Walker, where RTG will return next summer. The relocation was especially disappointing to Lucy Massopust, 30, who usually watches the show from the patio of her parents' condo overlooking the Walker.

That Massopust still chose to attend despite losing her own makeshift VIP was a testament to the festival's continued appeal, whatever the site.

"They do a nice job changing it up every year, so you always hear a few good bands you've never heard before," she said.

There was at least one clear shortcoming with the Boom Island site: Fans were hotheaded about having to wait in line around 20 minutes for the insufficient supply of free water.

"Eight faucets for 14,000 people is pretty ridiculous," said Trevor Maiers, 39, a veteran of past Rock the Gardens. "They should've at least changed the policy and let people bring in their own water. They knew it was going to be this hot."

Still, many of the fans waiting in the long water lines found it hard to complain too much.

"It's all part of the outdoor summer concert experience," said Jeremy Schouveller of White Bear Lake, another RTG regular. "I'm happy it's that time of the year."

Read a set-by-set review of Saturday's Rock the Garden concert and see more photos in Monday's Variety section or at startribune.com/music. Chris Riemenschneider • 612-673-4658 @ChrisRstrib