90-degree heat? Fine. Constant rain? Easy. If you can’t stand unbearable weather conditions, find yourself another festival.

Chicago’s most notorious music festival lured music lovers and partygoers alike into Grant Park only to trap them under stormy skies, muggy heat and a lackluster amount of the city’s fabled wind. Yet, even as the thermometer steadily rose, the festival grounds filled with increasingly large crowds each day, proving once and for all that

Lollapalooza is not a festival for the weak of heart.

Most music festivals ditch the big-city atmosphere for quiet, rural towns that offer campgrounds and allow for some semblance of personal space. Most music festivals offer up non-musical activities like tents for art vendors and open lawns for frisbee.

Lollapalooza sets its stages in the heart of downtown Chicago, the city skyline towering over the trees of Grant Park, leaving no room for camping. Lollapalooza crams over 130 acts onto seven stages in three days, permitting no time for recreational activities. But Lollapalooza is not most music festivals.

Friday opened with acts like Hockey, Manchester Orchestra and The Gaslight Anthem catching the crowds while the rain that would last all day still seemed trivial and amusing. In fact, for the first few hours, the rain was almost welcomed by festivalgoers who splashed in the puddles and slid on the slippery mix of clay and sand from baseball diamonds. A group of attendees even cleared an area in the mud to sculpt a mini version of Giza. But by Bon Iver’s 4 p.m. set, the rain was less amusing as soggy shoes weighed people down and umbrellas blocked views of the bands.

So I made my way over to Perry’s stage — home of the weekend’s electronic acts — to see Hollywood Holt, a Chicago hip hopper beloved by locals. It was by far the most energetic set I saw that weekend. Hollywood warmed the weary crowds into a dancing frenzy. Revived, I went on to catch a beautiful set by the Fleet Foxes, and fortunately the rain subsided.

Later, Janelle Monáe joined Of Montreal for a cover of David Bowie’s “Moonage Daydream,” her pompadour hair fitting perfectly with Of Montreal’s feathery, flamboyant get-ups.

Depeche Mode stole a lot of the crowd from Kings of Leon to wrap up day one, delivering a performance as creepy and cool as ever. Once a rock star, always a rock star.

Saturday got off to a late start as Atmosphere jammed for a slow growing crowd and Joe Pug played his blend of folksy rock to a seated crowd taking refuge at the small and shady BMI stage.

But when Artic Monkeys took the stage, the crowds began moshing, despite the heat. The set served as a catalyst for a run of high-energy performances by Santigold, TV on the Radio, Lykke Li and Animal Collective.

Stepping onstage in an oversized Indian headdress, Karen O and the Yeah Yeah Yeahs capped off the night with a ridiculously quirky and fun performance. The set was high in entertainment value and provided some of the more memorable moments of the weekend.

The Foxes returned to give a surprise show late Saturday night after festival hours at The Metro in Chicago’s Wrigleyville neighborhood. Opener Dungen won the hearts of the sold out crowd. The psychedelic Swedish rockers even earned an encore, unusual for an opening band. The encore was so unexpected that even Dungen seemed confused and didn’t know how to handle the situation, humbly asking, “It’s the Fleet Foxes you came to see, no?” But with a little encouragement from some of the Foxes on mics backstage, they fumbled back to their instruments for a final song.

By the time Fleet Foxes came on, steam was rising from the sweat-beaded glasses people held in their hands. But despite frontman Robin Pecknold’s admission to being drugged up on cold medication and suffering from heat exhaustion, the Foxes put on a powerful show.