Rain was a problem for the three-day music festival for the previous two years, causing major damage to the grass at Grant Park.
He sings about cheeseburgers in paradise, but some Jimmy Buffett fans say they got mud baths in hell at a weekend concert in Chicago.
A woman trying to clear a beaver dam got stuck in mud up to her chest for about five hours on Monday.
Heavy rain plus thousands of Lollapalooza concert-goers stripped away much of the grass and left mud behind over the weekend.
Rainstorms on Saturday forced the temporary evacuation of Lollapalooza, but after the crowds returned, some of the fields of Grant Park were left covered with mud.
The busy intersection of Cermak Road and Harlem Avenue was awash in mud Monday morning, after a water main broke beneath the pavement.